I saw that trending too so I checked his stream to see why.  I never figured it out, but then I didn’t go back all that far.  As far as I could tell, he was going for a million followers (to promote a charity, I think) and he was tweeting a lot.  Maybe that annoyed people? and they started the unfollow thread.  Then some of the tweets got out of hand (and some were quite funny, actually) and it grew and grew…

That’s just what I’m piecing together and I could be totally wrong.

Peggy