bluntforce - 6:45 am on Apr 14, 2012 (gmt 0)
While I'm still digesting what has been reported, I don't see Netmeg's issue as a defined negative SEO tactic. Could turn into that, but for now, it appears to be a waste of resources.
I just limited user agents, while I certainly block a few valid users a day, hundreds of bots also get blocked. As long as the majority of users have a good experience, I've done my job.