This week, Mihai Pătraşcu -- a theoretical computer scientist at AT&T Labs -- wrote a blog post in which he discussed his recent academic job search. I can't comment on his work, being well outside my expertise; but many people in his field (like Mitzenmacher, where I found the link) clearly think of him as talented. Pătraşcu's post is (in part) about his interview at UCSD -- they gave him an offer, but only after their first choice turned them down. On the basis of being ranked second, Pătraşcu declined the offer.
Pătraşcu mentions that, on the whole, his job search went less well than he expected: he didn't get interviews at many of the "top places" he applied. But down in the comments, we read:
I was on a hiring committee in one of these schools that decided not to interview you. Although I hesitated to post this comment, I think what I have to say will be helpful to your career. The reason we decided against further considering your case was because of your reputation as a very difficult, arrogant, and opinionated person. We even read your blog and found many posts that confirmed this reputation.
Of course, this anonymous commenter could be anybody. But the tone of Pătraşcu's post is certainly abrasive, so it is quite plausible that a hiring committee would have looked at similar posts and decided not to interview him.
I'm ambivalent about this. On the one hand, if his blog is representative, this guy wouldn't be fun to have as a colleague. On the other hand, I'm worried about the chilling effect -- it would be too bad if young researchers stopped blogging for fear of damaging their careers.