The 18-year-old subject of the article, whose "post-Facebook" peak flow—the measurement of a person's ability to breathe air—was reduced by as much as 20 percent, was signing online to look at his ex-girlfriend's profile. The stress of seeing how totally over him she was, and how cute she looked, and who is that guy in that picture, no, don't tell me, do you think they've had sex yet, caused his breathing problems. (He had actually created a separate profile to look at her and all the fun she was having without him, which perhaps speaks to other, larger, psychological problems at play.)
Obviously, the knowledge that social stress and anxiety can induce asthma attacks isn't exactly new. But, the authors write, Facebook is "a new source of psychological stress," and doctors should keep their eyes out for Facebook-induced asthma attacks. Ten years ago, when you got dumped, you could only imagine all the hot guys your ex is banging—thanks to Facebook, you can actually see every single one.
The only solution, then, is to ban easily-stressed-out people from Facebook. Poor asthmatic kids! Not only do they have no friends, but they'll never make any, now that we know Facebook will actually kill them.