This petition was rejected

The Government e-Petitions Team gave the following reason:

Complaints about a particular website’s content should first be directed to the site’s manager. Most Acceptable Use Policies (AUPs) already contain a general clause which allows ISPs to remove sites or content which contain offensive or objectionable material, even if it is not illegal. Arrangements similar to AUPs apply to many websites, including social networking sites.

Those people, who find user content offensive or suspect, should therefore report their concerns to the appropriate social network site.