We usually think of Facebook as a place to either keep in touch with real friends or cryogenically freeze old and artificial ones that wouldn’t otherwise exist. But a new Pew study says FB can actually end relationships, too. Naturally!

According to the study, “The tone of life on social networking sites,” 15 per cent of adults and a whopping 22 per cent of teens (volatile teens!) “had an experience on the site that ended their friendship with someone.” Ended! Permanent friendship cancelation! That’s over 1 in 5 teens on Facebook (the study also mentions LinkedIn, but really, nobody’s taking offense to a resume) who have IRL spillover from online nastiness. Enough so that they’re calling it quits with another human.

But what could be that bad? A racist status update? An offensive photo comment? Facebook allows you to meticulously craft a persona, if you so choose — so you’d think people would be smart enough to filter out something that might compromise an actual friendship. But you’d be wrong, because people are stupid, and Facebook is comprised of 800 million of them. Either we’re getting more sensitive, or the engorged definition of friendship Facebook’s prospered from can cut both ways — easy come, easy go.

It gets worse than friend spats, however — like, physical brawling bad. The study also claims three per cent of adults “had gotten into a physical fight with someone based on an experience they had on the site. Some eight per cent of [social network-using] teens said they had gotten into a fight because of what happened on the site.” A fight could go anywhere from a slap to getting thrown through a window, so there’s some breadth here. But a physical fight stemming from Facebook transgression seems radical. Extremely radical. This means there are social problems, originating on a place we share links and party photos, that not only can’t be solved online, but require violent physical contact.

The spread of Timeline, a more vibrant and robust way to browse the Book, can only mean more vibrant and robust arguments and hair-pulling matches. Be careful what you say about that new cover photo. [Pew]