User blog comment:Kirkburn/Technical Update: June 22, 2015/@comment-3060206-20150623162544/@comment-3060206-20150623171721

I'm not certain because we've really only been banning one user account who constantly enters and exits chat, causing a disruption to the users there. He is usually away from chat during those times (we have asked him) so the chat mods typically issue the two hour ban so that it expires by the time he returns.