Folks, the OP has a very concrete question - how much liability does he face, and what should he do? There is no point in waxing philosophical about copyright laws and motives, society, world peace, and all that - it's really quite OT. To the OP - there is nothing for you to do but wait. You already removed the offending material. The next move is the rights holder's. If s/he decides to take legal action, you must hire a lawyer. It is entirely possible that s/he'll look to settle with you for some amount under the threat of taking you to court - take that offer of settlement and hire a lawyer, because you must make sure that the offer is legit and they can't come back to you for a second bite, so this needs to be overseen by a lawyer; whether it makes sense to settle - also a question for a lawyer. For now, all you can do is get recommendations for a lawyer/solicitor, await the next move by the copyright holder upon which you then go ahead and hire the lawyer. The best outcome for you would be for the rights holder to forget it, as they made their point. Regardless of the outcome, hopefully you learned a lesson: never leave yourself unnecessarily exposed to legal liability. Best of luck!