Forum Moderators: not2easy
If you are concerned that the accomodation owner might actually follow through, I'd consult a lawyer--but in my opinion they are probably trying to scare you. I would assume it would be difficult and expensive for them to take you to court....
You know, if I were you I'd try negotiation first. Tell him that you are not responsible for the reviews on your site, and offer to post a response. Why not? You keep the reviews, your site gains credibility by allowing different views, he gets to state his side of the story.
We have probably averaged 2 threats of legal action a year on our review site, and none have ever been filed. The cross border issue makes it even less likely. Acording to the laws of most countries, they have to actually serve you, and convince their local courts that they do in fact have juristiction.
The journal also has a number of other articles worth reading.