“Fair Use” is the component of U.S. copyright law that allows you to use another copyrighted work without permission. There are many good sources of information on the internet, but here are a few big things to remember:
There is no clearly delineated point at which you can know your use qualifies as “fair”. It’s really more about analyzing how much risk you want to take and weighing that against reward. It’s ultimately a court’s decision on whether or not your use a fair one.
Factual information is not copyrightable.
A court generally determines fair use based on four key factors: How much of the copyrighted material was used; the purpose/character of the work (e.g. commercial vs. educational); the nature of the copyrighted work (fictional vs. factual); the effect of the use of the copyrighted work on the marketplace (does your use take money from the original creator).
“Errors and Omissions” insurance (E&O) exists for filmmakers looking for protection against potential litigation. Be aware, however, that like any insurance company, they will have lawyers who will first vet your case and the probability of your content triggering a lawsuit. You’re essentially paying for legal consultation, plus insurance, still with no guarantee that a lawsuit won’t arise. Even if you’re not ultimately personally responsible for paying those fees, the process is a major impediment to distribution.
In the case of content posted to YouTube®, it’s worth remembering that you pay nothing to post on a public platform, but Google bears an enormous litigation risk as the distributor. Given the scale on which YouTube® operates, don’t expect them to care about you or listen to your argument that your content complies with fair use should you receive three copyright strikes and have your channel shut down.