Complicating its efforts to accelerate advertising revenue, Facebook has agreed to make it clear to users that when they click to like a product on Facebook, their names and photos can be used to plug the product. They will also be given a chance to decline the opportunity to be unpaid endorsers. The changes are part of a settlement for a class-action lawsuit against Facebook in Federal District Court in California. The agreement compels the company to change one of its most effective advertising tools, known as Sponsored Stories. Read the full story at The New York Times.