Facebook posted the following statement - “Beginning [today], we will implement a new review process for determining which pages and groups should feature ads alongside their content. This process will expand the scope of Pages and Groups that should be ad-restricted. By the end of the week, we will remove ads from all Pages and Groups that fall into this new, more expansive restricted list.”
This review in process was made in response to some concerns from larger companies who advertise on Facebook who noticed that their ads were appearing alongside other ads containing inappropriate content. This kind of placement makes users doubt the validity of the company or ads and are less likely to click-through. Facebook will now evaluate and restrict ads that contain sexual, graphic or violent content. They have posted their community guidelines for business' reference which all advertisers are asked to comply.
Facebook has grown into a large and expansive social network which complicates the process of monitoring page content for validity and appropriateness. This enhanced security is just another step in which the social giant is working to ensure that the personal Facebook experience aligns with their interests which in turn keeps the value high for companies looking to advertise.
Remember - you can report an ad as inappropriate which will help Facebook continue to improve your experience.