So says this article on the BBC News website.

Not really sure that Facebook is the place that people “share documents and collaborate in ideas” but it’s certainly true that it can help teams and colleagues gel together. It’s a bit like the pub session after work where you find out things over a beer with someone that you never knew, and would probably never have known with just a polite chat next to the stationery cupboard.

In a similar way to the culling of available friends in my Messenger list during working hours, there are disadvantages to not giving people freedom to communicate online in the workplace. I know I’ve pinged questions to friends over Messenger that were beneficial in a work-related way, that I wouldn’t have bothered picking up the phone for otherwise.

Obviously you’ll always get people that take advantage of these things, but the same people will find other ways to time-waste online anyway, regardless of the channel.