Cosby filed a complaint with the World Intellectual Property Organization after learning of the infringement. The man who registered the name did not respond to the complaint. The WIPO arbitrator found that the domain name, fatalbert, "was identical or confusingly similar" to "Fat Albert," which seems hard to dispute. He awarded control of the domain to Cosby, although when I checked it just now it had the stupid bear story still on there (I left before I could get diverted to anything immoral, of course).
Various real celebrities have gone through a similar process to retrieve their Internet names, including Madonna, Pierce Brosnan and Carmen Electra. It is good to know that Carmen Electra has at least some intellectual property.