There's a lot of folks who don't play nice on the internet, and the feds increasingly are targeting them.
The FBI has established the Internet Crime Complaint Center (IC3) pursuant to which it collects complaints on a broad array of online activity ranging from spam and hacking to identity theft and financial fraud, and depending on the nature of the complaint the matter will be referred, if necessary, to the appropriate law enforcement agency for further action.
I can personally attest that the IC3 is user friendly. Over the last week a number of individuals with Yahoo user IDs have deposited messages with subject lines like "NEW FACEBOOK FOR ADULTS," "HERES THAT NEW ADULT SITE BY FACEBOOK" and "DO YOU THINK IM SEXY" into the Conversations folder of my two email accounts even though neither address is widely circulated. In any event, each of these individuals -- email@example.com, janarahillyps66 and hermelindasanks781 -- has been reported as suspected spammers of objectionable content (to me, at least), and it's important for people who similarly feel harassed by such apparent spammers to complain in order that the feds can determine who to target for enforcement action as the worst offenders.
Frankly, Facebook probably won't be too thrilled to learn that its name seemingly is being used to promote some adult site.