“If you have a friend that is adding you to groups you do not want to belong to, or they are behaving in a way that bothers you, you can tell them to stop doing it, block them or remove them as a friend — and they will no longer ever have the ability to add you to any group,” she wrote in an e-mail. “If you don’t trust someone to look out for you when making these types of decisions on the site, we’d suggest that you shouldn’t be friends on Facebook.”