Facebook on Monday will tighten its review process to spare advertisers the embarrassment of having their ads pop-up on pages containing porn or violent imagery. \"Our goal is to both preserve the freedoms of sharing on Facebook but also protect people and brands from certain types of content,\" the leading social network said Friday in a blog post. \"For example, we will now seek to restrict ads from appearing next to Pages and Groups that contain any violent, graphic or sexual content.\" The move appeared aimed at calming advertisers\' concerns about brands being tarnished by appearing on Facebook pages with offensive content. \"Prior to this change, a page selling adult products was eligible to have ads appear on its right-hand side; now there will not be ads displayed next to this type of content,\" Facebook said. The review process will be manual at first, but in the weeks ahead Facebook will build an automated system to block or remove ads from pages with controversial content. \"We\'ll do a better job making sure advertising messages appear next to brand-appropriate pages and groups,\" Facebook promised.