What happens when someone changes their license on an image (or other file) and you are actively using it on your website? Say I find a CC0 (public domain) or other Creative Commons Share Alike (permissive license) image on Flickr or the web. Or any asset/file really, that is under a permissive &quot;you can use this royalty-free/copyright-free/etc. for commercial purposes/etc.&quot; license. Say I use that image on my website, or that audio file, or video, or document. All is fine and well because the license was permissive. But then say the original content creator changes their license to be more restrictive, that is, you can't use it for commercial purposes, or other restrictive limitations are placed on the image/file. But I am already using it, given the old license. What am I to do now? There's not really an easy way to be notified of file permission changes on the web. You'd have to wait for the author to manually tell you they did that. Even if they did tell you they changed it, what is to be made of the fact that you used it when it had a permissive license? One example of this is on Flickr. I am not sure everyone is aware of how licensing works who uploads photos to Flickr. So say they had a permissive license at first, then they see someone using their images for commercial purposes, and then they go and change the license of those images to be more restrictive (disable commercial use, for example). The person using the author's images used them when the license was permissive, but now the license is restrictive. What happens in this situation? For any file type, or if that's too complex then I'm mainly interested in image/audio/video, or just images. Can the one using the author's file say &quot;I started using it when the license was permissive, so I am free to use it now even though you changed the license&quot;? Or what happens exactly in this situation, from a legal (and potentially practical) perspective? Must you take down the image after that? If you are required to take down the image after you used it when it had a permissive license, that seems like pandora's box, and you can't trust any image, because what if someday they decide to make all their images restricted but you are using thousands of them from when the license was permissive? Then there is the problem of proving the license was permissive at first, before it was changed. Flickr doesn't have license change logs, so maybe you would have to add the URL of the image to the wayback machine on archive.org to &quot;prove&quot; it was permissive? I don't get what you would have to do to make sure that, if you used an originally permissively licensed image/file, and then the license changed to more restrictive, that you won't get into trouble.
The creative commons licenses explicitly include a paragraph that they cannot be revoked once granted. That is an important concept of all free licenses (CC, but also MIT, Apache etc) Now it's a fact that Flickr (and maybe other sites) do allow changing the license to something less permissive. If you use one of their images, it's really best to keep a proof that it once was available under the CC license you originally got it with. This can be e.g., a screenshot or a link to the wayback machine. Wikimedia commons is often affected by this problem, as people regularly upload files from Flickr (which is absolutely ok, if they have a CC-by-sa or similar license at the time of the upload). Commons has installed a review process for such uploads. Trusted users check that the uploaded files really have the license on Flickr that the uploader declared. If later the license on Flickr is changed by the original owner, the history on Commons is considered to be enough evidence that the license was, in fact, permissive earlier. More about this can be read here.
In general, using content provided by another who incorrectly posted it under a permissive license, such as a CC license, does not grant a valid license from the real copyright holder. That is, if A writes some code (or a song, or creates an image, or whatever else), it is protected by copyright. If B then posts it to the web, with a statement that it is released under a particular license, without having obtained permission from A, then B's &quot;release&quot; is of no value, because B had no rights to grant. If C downloads and uses this content, relying on B's license, then A could take legal action against C. C would probably be considered (in the US) an &quot;innocent infringer&quot; which reduces the minimum statutory damage amount, but does not otherwise change C's legal position. A could, if it chose, bring suit and possibly obtain a judgement including some damages. But to return to the practical case of code posted on one of the SE sites. Given the comparatively short code sections usually posted, and that they do not usually form a complete working program, and given further the stated educational purpose of SE, it is likely that in US law such a posting would constitute fair use, and in the law of other countries fall under one or another exception to copyright. That is a general conclusion, the details would matter. I have not heard of a case similar to that suggested in the question. I find it unlikely that an SE poster would post copyright-protected code without permission, that is valuable enough to be worth an infringement suit, and substantial enough and having enough effect on th market for the original to be outside the protection of fair use. Such a situatiion is, of course, possible, even if unlikely. Note that a cease-and-desist letter is not a court order, and is really only a threat of court action. its only legal effect is to put the recipient on notice, so that continued infringement is not without awareness of the copyright claim. To have legal effect the claimant must actually bring an infringement suit, which is not without cost.
Online file converters are legal: there is no law that prohibits a person from making a program available and executing online, including creating output in the form of a file. It is possible that some person may illegally copy copyright-protected material then use a website to modify that material, in which case the question of vicarious liability for copyright infringement could arise, so we appeal to the DMCA safe harbor provisions to see what the website must do. First, the owner of copyright must submit a properly constructed takedown notice to the website. Crucially, the notice must contain sufficient information that the website operator can find and take down the item(s) in question. Assuming that the complainant can supply the &quot;where is it&quot; information, then there is a notice and counter-notice routine where the uploader is informed and can deny the accusation – the website operator doesn't evaluate the merits of the claim, he only sees that the formalities were observed. If the operator follows the rules, he cannot be held vicariously liable. If the link does not expire and if it is somehow promulgated, the technical potential for being a contributor to copyright infringement becomes very real, but it puts the operator in no worse a legal position than Youtube. So the question is not just related to OCILLA, it is entirely covered by that law. Questions of how users or website owners are &quot;supposed to&quot; act don't figure into this. If the website owner does not comply with those provisions, they have no access to the safe harbor provisions, and they can be sued. However, the website itself remains legally &quot;permitted&quot; (there never was a prohibition of such a website).
I assume these are digital photos that were electronically transferred (not prints physically delivered). If they were prints physically delivered, he owns those prints, since you used to own them but you unconditionally transferred ownership to him by giving them. No backsies under the law. The photos are protected by copyright law, which means that the person who took the pictures has the exclusive right to make copies, disseminate them, and authorize making copies. In order for anyone to make a copy, they need permission – a license – from you. In the world of pre-planned business deals, the copyright holder writes up a document granting B some right to use the protected material, which typically means "you can install it on your various devices but may not give copies to others". In this case, however, you didn't create an explicit written license. So if this ends up in court, the question is what implicit license you granted. The courts will not decide that you granted him the license to unrestrictedly sell or give away copies of the protected material. The most likely outcome would be that he can only keep his copy, i.e. he will not be forced to erase the copy that you sent him. What the courts would do is try to discern what license you most likely intended to grant to him. There is a provision in copyright law that allows a licensee to make backup copies of a computer program (17 USC 117), but a digital photo is not a computer program. So the lifespan of the copy that you sent would be the lifespan of the phone (I assume) that you sent it to. Since actually using a digital photo technically requires making a copy (from disk storage to computational memory), there is a legal direction (dead-end) that you could go where the photo could exist on the phone, but never be opened again. Again, the courts would have to discern what license you probably intended w.r.t. ever opening the photo – obviously you intended that the file could be opened / viewed any number of times. You could argue that the license which you granted was conditional, i.e. "you can have and use these pictures as long as we are a thing", but establishing that this was part of the license would be tricky. Free digital content often has some "as long as" condition attached to it, i.e. "you can use this program as long as you are affiliated with University of Whatever". I don't consider a conditional license to be a ridiculous interpretation, on the other hand the particular court (judge) might decide that people who sext should be forced to live with the unpleasant consequences of their decisions. If we exclude such a line of thinking, I don't see a compelling counter-argument that your ex-partner inequitably loses a right by construing the license as conditional. I don't know if there is any case law that addresses this: at any rate, copyright law would severely limit what he could do with the pictures (the tort "invasion of privacy" also limits dissemination).
If your app is published under US law, then the DMCA would apply, just as if it was a web site. The DMCA doesn't say anything about what particular technology the distributor is using. TO be protected by by the DMCA's &quot;safe harbor&quot; provision, you will need to include a notice in your app that you accept takedowns, and provide an address or method by which they can be sent, and an agent who will receive them. (You can be your own agent if you choose.) When and if you recieve a take down notice, you must check if it is valid in form. According to this Wikipedia article, a takedown notice must include: (i) A physical or electronic signature of a person authorized to act on behalf of the owner of an exclusive right that is allegedly infringed. (ii) Identification of the copyrighted work claimed to have been infringed, or, if multiple copyrighted works at a single online site are covered by a single notification, a representative list of such works at that site. (iii) Identification of the material that is claimed to be infringing or to be the subject of infringing activity and that is to be removed or access to which is to be disabled, and information reasonably sufficient to permit the service provider to locate the material. (iv) Information reasonably sufficient to permit the service provider to contact the complaining party, such as an address, telephone number, and, if available, an electronic mail address at which the complaining party may be contacted. (v) A statement that the complaining party has a good faith belief that use of the material in the manner complained of is not authorized by the copyright owner, its agent, or the law. (vi) A statement that the information in the notification is accurate, and under penalty of perjury, that the complaining party is authorized to act on behalf of the owner of an exclusive right that is allegedly infringed. (See the actual text of the relevant section of the law.) If you receive (through your designated agent) a valid takedown notice, you must promptly remove the content and notify the poster (or you can instruct to poster to remove it, but you must do so yourself if the poster does not). If the poster then files a valid counter notice (see the linked sources above) with your agent, you must notify the sender of the original notice, and if the sender does not notify you of a copyright suit filed within 10-14 days, you must restore the content. Provided that these rules are complied with, the host gets a 'safe harbor&quot; and cannot be sued for copyright infringement, nor for the act of taking down the content. I believe that the agent must be registered with the US copyright office. The courts have not ruled on just how quickly an ISP or other host must react to the takedown notice. It must be &quot;expeditious&quot;. Moreover, Under the DMCA (i) 1) (a) The host must have, post, and enforce a policy denying access to repeat infringers, or lose safe harbor protection. The text of the provision is: (i) Conditions for Eligibility. -(1)Accommodation of technology. —The limitations on liability established by this section shall apply to a service provider only if the service provider— --(A) has adopted and reasonably implemented, and informs subscribers and account holders of the service provider’s system or network of, a policy that provides for the termination in appropriate circumstances of subscribers and account holders of the service provider’s system or network who are repeat infringers;
The notification that you saw is not useful legal information for you: stuff always belongs to whoever owns the stuff. It might be interpreted as saying "it doesn't belong to us", but you can't count on that (it's virtually guaranteed that at least some of the content there is owned by the website owner). A more informative statement would be "You will have to get permission from the content owner to copy their stuff", and "We're not going to spend time figuring out who owns what". You could read the terms of service (try this with Stack Exchange) to see what the site tells people. The TOS here says that if you contribute anything, it "is perpetually and irrevocably licensed to Stack Exchange under the Creative Commons Attribution Share Alike license". You can then look up what that license says and learn what that allows. Websites are kind of tricky, though, because it's not hard to change the wording of a TOS, and you need to know what specific TOS was promulgated at the time a particular contribution was unleashed. Usual practice is to think it through carefully and not frequently tweak the TOS, but it's not illegal to change the TOS. Note that copyright law does not prohibit you from using other people's stuff, it prohibits you from copying. The distinction is clearer when you see a post that explains an algorithm with actual code, you read and learn and make use of that, but write your own code. As a user out there, if there isn't a clear indication that stuff posted is there for the taking, under some public license (as is the case with SE), then getting specific permission to copy, from the owner of the content (possibly untraceable), would be necessary. Now assume that you're a moderator or site-owner of some forum: presumably (hopefully) you have a TOS that addresses that situation, which says that moderators have the right to edit or delete content at their sole discretion, and also you say what kinds of posts are prohibited. Such an statement is not absolutely mandatory for all things, but it may be necessary to avoid litigation over some acts. One one end of the spectrum, it would be illegal for a forum to host child porn, stolen credit card numbers, or protected digital content. If a user were to post such stuff, the site would need to eliminate that stuff, and the poster could not legally rely on an argument of the type "That's my stuff, you have no right to mess with it". On the other hand, if a forum actually requires paid membership, then there may be a strong contractual expectation that the user is getting something of value, so you would have to watch for statements that could be interpreted as broad permission to put stuff out there without any interference. (For instance, a file-hosting service would have only minimal restrictions on content, aimed at protecting their own legal interests; whereas a political-advocacy site would have maximal interest in prohibiting the expression of views counter to the cause). Thus the SE TOS has you "grant Stack Exchange the perpetual and irrevocable right and license to use, copy, cache, publish, display, distribute, modify, create derivative works", which allows moderators to correct typos, delete offensive wording, and obliterate entire posts. If a site fails to have any such clauses in their TOS, then it might be a matter that has to be settled in court, whether they have the right to eliminate "spam" (i.e. advertising for a service, especially if the reason for getting an account was to provide an advertising platform). In light of the limited use sanctioned by the TOS, per the below comment, legal copying will be quite limited. However, "fair use" a situation where copying is allowed, regardless of what the TOS may say. (You could be banned from the site, but you could not be sued for infringement). Fair use was invented precisely so that people could make comments like "Jones advocates an absurd law, saying '...[quote from Jones]...'". Thus you can comment on a post and quote the relevant part ("The lines '[... quoting the code ...]' results in an infinite loop"). See the Fair Use FAQ for more details.
Exactly the same way it works over all other content There are no special classes of copyright, there’s just copyright. What a user of a service may do with copyright materials will be spelled out in the licence. If there is no licence, then they are left with fair use/fair dealing.
When you license your IP (like a song) you can specify the terms and conditions of its use by the licensee, including revenue shares from any derived work. However, if, as your comment suggests, you grant an "informal" license, and later decide that you want to "firm things up" with a license having different terms, that's a matter you would have to either negotiate or litigate with your counterparty. If you want a common reference point for negotiation of this sort of license, you might have a look at compulsory license terms.