Last modified: 2008-04-14 16:16:55 UTC
The MediaWiki:Anontalkpagetext (http://en.wikipedia.org/wiki/MediaWiki:Anontalkpagetext) appears on all IP address-like usernames up to 999.999.999.999 even though none above 255.255.255.255 are actually valid IP addresses.
The underlying bug here is that User::isIP() returns true for all strings that match the regex /\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}/
fixed in r33290.