It's quite aggressive. I'd created a legit account and commented twice in one day, and was flagged on the 2nd. It soured the little garnered appetite for trying out Twitter.

OTOH I can see why they've stepped up their efforts, I think historically it was the easiest one to sign up accounts en masse.

Yeah, I believe they have the biggest problem with abuse, fake accounts and spam than all of the networks. Drastic measures have to be taken if they are serious to remain a valuable social network.