They most likely have to keep login time and IP (terrorist laws and all that); that can lead to the ISP that may or may not be US-based. If it is (and the judge

They most likely have to keep login time and IP (terrorist laws and all that); that can lead to the ISP that may or may not be US-based. If it is (and the judge grants a warrant, which appears likely) then you have a narrower base of users to consider. If the comment is from somewhere outside of the US, unless it’s suddenly a trend to cross an ocean to have your carpet cleaned, Yelp would have to consider the possibility that the comments might have been fake, face little legal consequences presumably, and erase those. I know I can be lack creativity, but… trolling a dodgy carpet cleaner half a world away? Seriously? The most convoluted case I'll consider is competition — and ever that seems far-fetched. Include here a ton of CSI-based scenarii on people using chat-room and web-cafés to communicate convoluted plot via dry-cleaner reviews, over-zelaous investigators and tech wizz using the ‘enhance’ button and green lines bouncing around the globe to trace the actual IP.