All Answers To Questions

You can sue anybody for anything...but....you'd better have a winnable case or you will be stuck for court costs and attorney fees if you lose.

If they falsely accuse you of copyright infringement, it would have to cause some harm to you in some way. Did you have to pay a lawyer to defend yourself against a frivolous lawsuit? Did it, realistically, damage your reputation among your friends,colleagues, etc.? If no harm has been done then you don't have a case.

Was it legally found that the claim was false? Usually a company won't go after someone for copyright infringement unless they have the means to spend time and money on it. If you were caught using music or video footage then that IS copyright infringement, Using lyrics, lines, book pages, photographs pretty much anything unless it's in Media commons IS infringement. If you think you have a strong case by all means go for it, but if you used even just a little bit, you probably won't win and you'll waste valuable money.

Lawyers can't give out advice, and if I were you, I wouldn't seek it from the internet. If you're serious about filing a claim because of some harm that resulted from those accusations, you should contact a lawyer, who may give you a free consultation (or may charge you for it). If the case has merit, the attorney will help you. If not, s/he will tell you that. Good luck!

Yes, if you want to waste a pile of time and money, you can sue for a declaration that your actions are not copyright infringement; you can also sue for defamation damages if someone recklessly accuses you of a crime (e.g., copyright infringement for profit), or if the false accusations put you (or your business) in a false light. Your lawyer can advise you on the particulars that may apply to your situation, and a good lawyer will advise you of the likelihood of winning anything.