Did they really think Facebook wouldn't notice? FacebookOfSex.com (previously owned by FriendFinder Networks) was able to live for about a year and had over four million visitors before Facebook was able to get the rogue domain shut down recently. Facebook now owns the rights to the domain name and has been very busy protecting its name and brand against several other trademark infringing domains.
Besides FacebookOfSex.com, Facebook is seeking damages in the amount of $100,000 and control from FaceSounds.com, Killfacebook.com, moneywithfacebook.com, friendsonfacebook.com and eighteen other domain names that are treading on the brand's name. According to the Facebook usage guidelines, when asked the question, "Can I used Facebook in my business name or domain name?"
The answer is, "No. Use of the Facebook trademark or something confusingly similar in your company name or domain name, even in connection with goods/services that are arguably unrelated to those offered by Facebook, can both create consumer confusion as well as dilute the distinctiveness of the Facebook brand and weaken Facebook's trademark rights."