Facebook published detailed guidelines Tuesday for what users can and cannot post on the social media service. Earlier this month, lawmakers called on Facebook chief Mark Zuckerberg to appear in Congress. They demanded that his company take more steps to protect the privacy of its users. Some even raised the possibility of regulating the social media service. Most of the newly-announced guidelines - which Facebook calls “Community Standards” have already been in place. But it is the first time Facebook has publicly shared complete and detailed information about all its restrictions on user content. About 7,600 Facebook moderators use the guidelines in examining Facebook content.