A New York dentist is accused of making patients sign away their copyright to negative reviews and then billing a patient $100 a day for posting unhappy reviews on Yelp. The dentist is now being taken to court.
Source: Dentist charges patient for negative Yelp reviews, suit says – CNET
This brings up some interesting questions about what it is okay to post online, where you may post it, and what other people (especially companies) may be allowed to do about it.