I own my network (ARIN registered) so unless they talk to our several ISPs and get our routes withdrawn we're basically the last line. I suppose the answer was always, "talk to a lawyer". It's a shame that it's so expensive.
Even if it's not worth it to "learn how to do it right" over a free tier user, it's probably good to get a policy established so that if it DID end up in court, you could point to it and say "we've always followed the policy as required to the letter".