Some bots mass block ed open proxies, used by some trolls to abuse the Wikipedia rules. This blocks, due to their large numbers, impede read the logs to CheckUsers, which analyzes them to check IP addresses of new accounts vandals and trolls. It also prevents ordinary users or admins from exercising control and verification. Need add the feature to the Special:Log „hide bots“, as on the Special:RecentChanges.
http://ru.wikipedia.org/wiki/Special:Log/block look at QBA-bot
http://en.wikipedia.org/wiki/Special:Log/block look at ProcseeBot