Friends don’t let friends become political enemies. A new survey by the Pew Research Center’s Internet and American Life Project shows that 9 percent of social-networking users have blocked, unfriended, or hidden someone because they disagreed over something about politics posted. Eight percent have done so because they argued about politics. (Read the report here.) But friends often disagree without comment: 73 percent of users “only sometimes” agree with friends’ political postings; 66 percent usually ignore the posts; 25 percent always agree or mostly agree.