I am unpersuaded with regard to accidental clicking. The keyboard shortcut issue, maybe. But I have a good inch of space between the FB tickybox and the "post comment" button on my browser. (Though I am fully willing to admit that I may well be atypical; YMMV, of course.)

My life is also a pretty low-drama zone, so my expectation for the worst thing that's likely to happen is friends seeing something so random and out-of-context that it makes no sense...