Stalker is an irssi plugin to record information on an IRC network and draw correlations between people’s current nicknames and nicknames they may have used in the past.

Some possible uses:

-	You have built a time machine and went back to 1995 and are currently being stalked by someone on IRC.  You DCC with the person and realize their IP is on the 192.168.0.0/24 CIDR.
-	Someone is evading your ban and your ban-hammer is twitching.