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.
Normal proxys act transparent, in this case it seems to be for a short time not. (You have to configure your webserver to use the IP submitted by the proxy, instead of the "requesting IP")
At least in this case, it's nothing we should worry about. It can occur if they switched, e.g. in case of any running DDoS, first to the DDoS protection and then reconfigured their webservers some minutes later.