Suing your fans: not just for conglomerates anymore

Prince is threatening to do it now, with some very expansive copyright and trademark claims. (Does he even own the copyright in the photos of him? Unless he set the timer and then jogged into place, this depends on various contractual arrangements.)

I wonder to what extent his experience in Pickett v. Prince, in which he was sued for making a guitar in the shape of his invented symbol after Pickett had already made a similar guitar, affects his attitudes towards fansites.