Odd. I'm pretty sure the guys there aren't malicious. I've met a couple of them. So I'd guess they got attacked at some point and got black listed.
Looks like they've cleared that out. I tried it again, and this time, no malware warning. Either that, or I'm already hacked.
Article here;
http://www.ox.ac.uk/media/science_blog/brainboosting.html
The article goes on to discuss the ethics of the technique.