Can someone use DNA samples that were scattered by their owners for commercial purposes? Artist Heather Dewey-Hagborg has collected DNA samples from cigarette butts and chewing-gums found on the floor to create realistic portraits of their former owners. I find this project fascinating, and although there are still some caveats in the likenesses and the technology behind it, it opens doors to several questions about ethics and the age-old race between technology and laws. Mostly, is this "discarded DNA" still "owned" by their owners after they flick it to the floor? (I am assuming that our DNA code belongs to us...)
Trash is public property, see here for example: "The abandonment of property is the relinquishing of all title, possession, or claim to or of it". I think the assumption that a DNA code "belongs to you" is legally questionable. If you don't abandon it, you can own specific molecules of DNA. The only way to legally control replication of that pattern (garnerd via trash picking) would be via copyright or patent. But natually occurring DNA cannot be patented (Assoc. for Molecular Pathology v. Myriad Genetics, Inc.). As a natural fact, it is also not subject to copyright.
Such clauses are called "copyright assignment", "invention assignment", and/or "works for hire" clauses, partly depending on the clause's intent and wording. They're pretty common in employment contracts for software development and some creative positions. Frankly, the clauses don't actually do much, at least in the US -- copyright law already recognizes the concept of works made for hire (which belong to the employer), and claims too far beyond that are often rejected if they aren't obviously related to company business. With that said, your hypothetical programmer's painting is safe unless it depicts, say, the contents of an email from the CEO. :) Even if the clause technically entitles the employer to claim ownership, the employer has no legitimate interest in doing so. Likewise, that app created outside work is safe as long as it is created using no company resources and is unrelated to the employer's business. If the app is obviously related, that's where things get hairy.
Here's where you went wrong legally: Suppose I legally obtain some digital image created by somebody else (e.g., by downloading from a public website). That, right there, is copyright infringement- unless the copyright owner has granted permission or the image is public domain you cannot copy it - this breaches "the right to make reproductions". By posting it on the web (assuming that it isn't itself an infringing copy) they have given implied permission for you to look at it in a web browser but not to copy it into a presentation even if that presentation is never presented. If it is presented then that makes the infringement worse - it adds breaches of "the right to communicate to the public" and "the right to use the work as a basis for an audiovisual work". How is this different from the computer wallpaper? It isn't. If you are using the one of the defaults that shipped with the OS then the license gives you permission. If you are using someone else's copyright without permission then it's a breach. There are defenses to copyright infringement but these are quite nationally variable - search this or other sites for "fair dealing" and "fair use".
Earlier this year, the Internet lawyer Arnoud Engelfriet wrote a blog post about exactly this topic. As it is written in Dutch, I will summarize it here: As you also said, deleting posts breaks the flow of the archived conversation and it makes your archive incomplete. This is a problem for the freedom of expression and information. But Art. 17(3) GDPR includes an exception to the right of erasure for this situation. So posts do not need to be deleted. However, profiles are not included in this exception. So they must be removed, but they can be pseudonymized. For example replace the username with user89432, and remove all details from the profile. If other posts contain the nick of the author of an anonymized post, that is considered an journalistic, academic artistic or literary expression, so Art. 85 GDPR would apply, so the right of erasure does not apply to that. Bottom line: you only have to pseudonymize the account, if that person wants to be removed from the forum.
If that which you describe in your comment ( Facebook post as only basis for warrantless search) is, and can be shown, to be the only basis for the search, and there was no evidence of a crime in plain view when they arrived.....then yes, it is likely the search and all evidence acquired from the search would be excludable. As to whether the individual could still be prosecuted, that depends if a case could be built independent of the evidence collected during the search.
Not all illegal things are crimes. Lack of evidence. They are asked to testify, and they say "what I said in my book was a lie". There is no general law against lying, except when under oath. Statute of limitations. Saying "10 years ago I did smoke drugs" means that any offence is no longer prosecutable. Lack of details. Which jurisdiction were they in? When did they commit the act, how many acts? You cannot be arrested for being a "bank robber" or a "murderer". You are charged with "robbing Bank X on 123 Fake Street the Thursday 25 April 2018" or "murdering Jim Thio in January 2017". Otherwise the defendant would have a hard time defending himself (how to prove that you have not killed anyone at any time?) All of the above combined with prosecutorial discretion in the form that any possible prosecutor will most likely determine that bringing charges would be just a waste of time and resources. UPDATE February 2018: Just for the sake of completeness, a reference to the situation of Jacques Cassandri, who did boast about a serious crime(a robbery in a Societe Generale vault in 1976) in a book. Unfortunately for him, he made some kind of mistake/miscalculation and the crime had not yet expired, so he has become an example of someone being prosecuted by confessing a crime in a book.
Against Bob: yes; Against Cindy: no I'm going to borrow @Trish's example because it's a good one although the conclusions they reach are wrong. Alice made a green box. Bob signs an NDA never to tell anyone that Alice made a green box, and there is a clause in it that if the NDA is breached, the box is red. Bob tells Cindy that Alice made a green box. Cindy has a patent on making green boxes. Cindy sues Alice and in the lawsuit puts Bob on the stand. Situation 1 So, the box is objectively green and objectively a breach of Cindy's patent on green boxes. Bob is on the stand and is required to answer questions honestly and no contract can prevent him from doing so. He testifies that the box is green. This would be a breach of contract except that a clause that requires a breach of the law (perjury in this case) is void for public policy reasons so Bob cannot be sued for this. However, he can be sued for the initial breach - he may have a public policy defense here because Alice was breaking the law, however, it’s easy enough to construct a scenario where Alice was innocent but suffered loss from Bob’s disclosure. Cindy can say what she likes because she is not bound by the NDA. Cindy wins, Alice loses. Situation 2 Cindy dies - after a long and happy life so we won't grieve too much. To Bob's surprise, he inherits Cindy's green box patent of which he was previously in complete ignorance of. Bob sues Alice for breaching Cindy's now his, patent. So, the box is objectively green and objectively a breach of Cindy's patent on green boxes. However, Bob agreed with Alice in the contract that the box is red and so, legally for matters between Alice and Bob the box is legally red (notwithstanding that everyone knows it's green) and is not in breach of Bob's patent. This sort of stuff has a name - a legal fiction. Adoption is a legal fiction - adoptive parents are (legally) parents; biological parents of adopted children are (legally) strangers. Alice wins, Bob loses.
It Depends If the person reusing the image (lets call that person R for reuser) is not complying with the terms of the Creative commons license, which include a requirement to provide attribution of the source work, then R cannot rely on the license, and the granting of the license ad the presence of a license declaration is legally irrelevant. R must have some other basis to reuse the image. This could be an exception to copyright, such as fair use or fair dealing. Or possibly the image is not protected by copyright, for example because its copyright has expired, or because it is a work of the US Federal Government being used in the US. In the absence of such a basis, R is infringing copyright. In much of the world copyright now lasts for 70 years after the death of the author (or of all co-authors). In some different terms apply, ranging from life+50 to life+100. Sound recordings and photos get shorter terms in some countries. In the US the term is life+70 for recent works, but for work created and published before 1978 more complex rules apply, depending on the date of publication, and whether laws on notice and renewal were complied with. See the well-known chart Copyright Term and the Public Domain for the various cases and when copyright expires in each case. The question asks about fair use. This is a US-specific legal concept. It is designed to be flexible, an is highly fact-dependent. As a result it is rarely possible to say if a use will qualify as a fair use with certainty until a court passes on it. See Is this copyright infringement? Is it fair use? What if I don&#39;t make any money off it? for more on fair use. Not providing attribution is itself often considered to weigh against fair use. The question does not give enough detail to make even a good guess as to whether such a use is likely to be held to be fair use. Identifying the kind of eagle has some educational value, which might favor fair use to some extent, but must be considered in light of the overall purpose of the use, which is not described. There is no indication as to whether the original work is creative or factual, or whether the reuse would be likely to harm the market for the original. Much use of images on social media does not stand up under a fair use analysis. Providing proper attribution might well help any fair use claim. See also Do you have to give attribution if an image falls under Creative Commons?