The social network says that on Monday 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 monthly users the freedom to post what they want and providing advertisers with space to sell their products.

In May, Facebook 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.