If we wanted to work, we wouldn’t be posting friend requests. The social networking giant is heading straight for workplaces with a new product supervisors might allow. Facebook at Work will function like the fun version — networks, groups, private messages — but will add document collaboration and other professional tools. It’s already used at Facebook HQ, but the public version is currently in the pilot stages. Work profiles will be separate from personal ones, so there’s no rush to delete compromising college-day selfies.