Tattoo the phrase CITE WHAT'S NOT YOURS on your arm, and you'll be happy forever.
Wikipedia says (emphasis added):
Fair use is a limitation and exception to the exclusive right granted
by copyright law to the author of a creative work. In United States
copyright law, fair use is a doctrine that permits limited use of
copyrighted material without acquiring permission from the rights
holders. Examples of fair use include commentary, criticism, news
reporting, research, teaching, library archiving and scholarship.
If your work falls under one of those categories, have some tea and go for a walk -- you have nothing whatsoever to worry about.
Otherwise, here are some general guidelines from having followed hobbyist game developers and news:
- If you'll earn enough money out of it to live (even if that money comes indirectly out of advertising on your site) do not use anyone else's licensed content. At all. Bob does work, Bob gets paid. If Bob gets paid for someone else's work, there's going to be trouble when that someone else finds out.
- If you'll earn money, but not enough to live off of, cite, make sure the licensed content is not the central core of your game and cooperate fully if someone asks their licensed content to be removed. Most likely, nobody will mind. Corporate types dig free advertising and indie types will just be flattered someone noticed them.
- If you will make no money (up to and including getting ad-revenue that just covers your server costs), cite what you use and you'll be good.
There will of course be exceptions, but this should cover almost all cases.