POPBot was the Preemptive Open Proxy Blocker bot. It scanned for open proxies and tried to edit wikipedia through them for verification, and then blocked them. Most of the anonymous edits to subpages of this one, where the bot in action.
For more information, see the discussions at Wikipedia talk:Bots/Archive 10#Open_proxy_blocker and Wikipedia talk:Bots/Archive 5#OpenProxyBlockerBot, or ask me.
Tests were run here, and an archive of old scans can be found at /archive.
Form letter for ISPs
editThere's an open HTTP proxy at $IP:$PORT, which sends all the requests it gets through the $ISP proxies. This is causing some trouble for us at Wikipedia, as we generally block open proxies as they're an easy way for vandals to disrupt our work. Doing so for the $ISP proxies would also prevent numerous good editors from editing wikipedia however; Could you please close this open proxy or prevent it from using your shared proxy so it can be blocked individually without causing collateral damage? Thanks in advance.