Hi, TechCrunch Europe reported the bug. I hope you fix it asap. It seems to work! I'm extremely sorry, did not mean to exploit it, was just trying to ascertain if it was true.
Once you are done fixing the bug, you will have the arduous task of reversing all the follows that took place by exploiting this bug. If you have an easy way to do that, well and fine. One thing I noticed, when you make someone follow you using the exploited bug, the "new follower notification email" is never sent. This might be of some help to you in identifying all those who exploited the bug and reverse it.