What is the amateur FM broadcasting legal limit? Some stereos can receive a signal just outside the commercial band at either end of 88 and 108. I legally can buy everything I need on eBay to transmit my own personal radio station. What legal problems may I run into not having a license for while transmitting on low power just outside the commercial frequency ban. What are my limitations to transmit a prerecorded, remixed and non-profit music freely?
What legal problems might you run into? Well, you'd be violating 47 USC 301, which requires a license for anyone broadcasting in the United States. Penalties for that are given in 47 USC 501 (a fine of up to $10,000 and up to a year in prison), 47 USC 502 (an additional fine of $500 per day of violation), 47 USC 501(b)(2)(D) (forfeiture of up to $10,000 per day, with a maximum of $75,000), and 47 USC 510 (forfeiture of your equipment). "Just outside the FM band" on the low end (below 88 MHz) is television channel 6, while on the high end (above 108 MHz) are frequencies used for airplane navigation. If your transmission interferes with a licensed user of channel 6, you're also in violation of 47 USC 333, which carries much the same penalties as violating section 301, but without the forfeiture of equipment. If your transmission interferes with air navigation, you're in violation of 49 USC 46308, which carries a penalty of up to five years in prison and a fine of up to $5,000. Honestly, you'd be better off broadcasting inside the FM band: there, you can broadcast without a license under 47 CFR 15, which limits you to a broadcast power of 250 microvolts per meter at 3 meters (basically, you can broadcast to anyone in your house or maybe the next house over).
It would not work. There is apparently a common misconception in Georgia that this would be the case, based on Article IX, Section II, Paragraph III (b)(1) of the Georgia constitution, which says: No county may exercise any of the powers listed in subparagraph (a) of this Paragraph [including police protection] or provide any service listed therein inside the boundaries of any municipality or any other county except by contract with the municipality or county affected. What many people miss is the clause right before that: "Unless otherwise provided by law." Georgia courts have held that the law does provide otherwise when pursuing someone for a traffic offense: The plaintiff contends that when the collision occurred, the policeman-deputy sheriff had no authority to be pursuing the Mitchell car because he was outside the county in which he had a power of arrest. While ordinarily a peace officer has power of arrest only in the territory of the governmental unit by which he was appointed, there are two exceptions to the rule present in this case. Code Ann. s 92A-509, which deals with arrests for traffic offenses, provides by implication that certain officers (including deputy sheriffs) have arrest powers for these offenses outside their appointed territories. City of Winterville v. Strickland, 127 Ga. App. 716, 718, 194 S.E.2d 623, 625 (1972). What that case decided in 1972, the principle was in place well before the boys began their hijinks. I don't know of any state where the law is different, though the answer would be different if the boys crossed into another state.
This very much depends on where you are. Different jurisdictions have wildly different laws about this. Some places are very permissive. You can record a conversation that you aren't even a party to so long as nobody has any reasonable expectation of privacy. In others, affirmative consent is required from every party to a conversation before it's legal to record it. The laws run the entire spectrum. Some places allow you to record anything you're a party to without permission, but you can't record others' conversations. Some places require you to disclose, but not obtain explicit permission. Some allow you to record but restrict who you can disclose it to. Some allow you to record or ban recording only under certain circumstances. It's a really wide gamut of laws. Since you don't say where you are, who you're recording, or why, there's no way to really answer the question. Here's a good rundown on the United States. This Wikipedia article covers lots of different countries, but only with regard to phone calls.
No, it means you can't copy it. By default, the copyright to a work is owned by its creator, and nobody else is allowed to copy it, or create derived works, without their permission. That permission can be granted by a license. "License unknown" doesn't really tell us anything, but it certainly isn't clearly granting you permission. So you don't have permission to copy, and thus you cannot. You would have to seek permission from the copyright holder. See also If no licence is distributed with an application/source code, what license applies by default if any? (Some jurisdictions do allow for "fair use" exceptions, which allow you to copy a work without permission. You haven't said what jurisdiction you are in.)
You are free to ask them to stop. If they do, great. If they don’t, you legal options depend on if they are legally able to make such noise at that time or not. I am not familiar with UK law but typical laws give wide powers to the owners of infrastructure to construct/repair it. Again, typically, permits may be required but exceptions exist for urgent work. If they have such a permit (or don’t need one) your legal options are nil. If they don’t you can go to court seeking an injunction to stop them until they do.
Everything is allowed unless the law says it isn’t Common law systems like the USA are ‘exceptions based’ - the law permits everything except what it prohibits. So, your question is backwards - rather than looking for laws that allow it, you need to look for laws that prohibit, restrict or regulate it. There are laws that regulate this but none that prohibit it.
A few years ago, there was a trial in the USA about some short sound on some music CD: One party claimed that one piece of music on the CD contained a sound of less than one second length which is copied from another CD without the permission of the copyright owner of the other CD. It could never be found out if this claim was really true. The court's decision was: If it is not possible to distinguish between a copy and a work that does not depend on the other work at all, it is not a copyright infringement - even if the sound has been copied from the other CD. For this reason, I'd guess that a 4x3 image would not be a copyright infringement, yet, while 60x45 would definitely be one. Just for reference: The same image as 3x4 and as 45x60:
http://www.wipo.int/edocs/lexdocs/laws/en/dk/dk091en.pdf is the Copyright Law in English for Denmark. You should probably try to find a Danish version to ensure the translation is accurate. Chapter 2 lists the exemptions from the general rule that you need the copyright owner's permission to use their IP. Unfortunately, the usage you have made does not meet the requirements for private use (s12): digital copies may only be shared among the members of one household, placing them on the web extends beyond your household. It may meet the requirements of educational use (s13) providing that your school has met the requirements for Extended Collective Use (s50). For photographs, this seems unlikely, such arrangements are usually limited to songs and television works. Under Chapter 6b, you are permitted to use "orphaned works", however, this requires that you have made a diligent search for the owners and have been unable to either identify or locate them. Copyright violation is subject to both penal sanctions (fines and in egregious violations imprisonment) (s76) and damages (s83). TL;DR Yes, you could be sued. Yes, the copyright holder would probably be successful. No, it is extremely unlikely they would bother.