MENLO PARK, California (AP) ? Facebook is pulling ads from pages that contain violence or sexual content. The social network said that on Monday, it will expand its definition of pages and groups that are too controversial to carry advertisements. Facebook has sought to strike a balance between giving its 1.1 billion users the freedom to post what they want and providing advertisers with space to sell their products. In May, Facebook Inc. lost more than a dozen advertisers, at least temporarily, after the activist group Women, Action and the Media urged an advertising boycott to protest hate speech on the Facebook site. The controversial content included grisly photos and mottos that encouraged rape, abuse and other violence against women. The company said then that it would review its guidelines, update training for employees and increase accountability for those who post such matter. It also said it would work more closely with women's groups. Some of the companies that initially pulled their ads ? including automaker Nissan and the car-sharing service Zipcar ? said then that they were pleased with Facebook's response. Facebook had already banned ads on certain pages. The new policy will expand on the categories affected by the ban. In the past, a company selling adult-theme products could have ads running on the right side of the page, for instance. Those pages will be ad-free starting Monday. "We recognize we need to do more to prevent situations where ads are displayed alongside controversial Pages and Groups," the company said in a statement Friday. "So we are taking action."