Has anyone Else seen this? These IPs do seem to be related to DDoS alright, a quick google of 209.200.185.88 leads to
http://www.prolexic.com/ a company specializing in DDoS protection "5 out of 10 world's top banks rely on Prolexic"
Although Googling the others seem to bring up proxy sites?
Anyone know what this is about? my knowledge of this sort of thing is somewhat limited.
Mt. Gox uses Prolexic. I don't know why that would have anything to do with logging into any one person's account. Maybe they were attempted logins for penetration testing (Despite people thinking Mt. Gox didn't give a crap about security, they apparently previously spent over 2000 BTC on security bounties). It's also possible that some people's IPs had to be whitelisted due to overambitious DDOS filters, which somehow might be an explanation.
Either that, or routing during the DDOS made it seem like a lot of people came from Prolexic which might have been routing traffic. Now I'm just guessing wildly, though. So maybe all the logged IPs that come up as Prolexic can be strung together and translated to give the secret location of the ark of the covenant.