Could you be sued for turning over an Internet user's sign-up information to law enforcement?

Just fyi - I wrote a new article on libraries and search warrants, telling the tale of an ISP that turned over subscriber records after it was served a search warrant. Problem was the search warrant wasn't signed by a judge, and now the ISP is being sued. I think the subscriber has a good case.

I really hope he wins - if not, it could be serious for all of us. If ISPs and libraries don't need to examine search warrants carefully, all of our rights as users are really diminished.

I didn't discuss the issue of contractual consent in the article, because libraries never (okay never say never, but I'd be quite surprised to find one) ask users to sign over this kind of consent in advance. If the ISP contract had a clause that the subscriber signed giving consent in advance, the case could blow. But I talked with the subscriber's lawyer a bit, and he tells me that the consent clause stated that the ISP would only give out the info pursuant to legal process.