Kill/stop/logout using skill command 15 Sep 2008
To manage the connected users (such as kill operations), you'll be using a small but nifty package called procps Your Linux distro should already have this package but if it hasn't, just install it.
PROCPS is the package that has a bunch of small useful utilities that give information about processes using the /proc filesystem (which is not a real file system but a way for the kernel to provide information about the status of entries in its process table). The package includes the programs ps, top, vmstat, w, kill, free, slabtop, and skill.
Ok, so here we go…Let's assume that our test user is called boo
# skill -STOP -u boo
Resume already halted user
# skill -CONT -u boo
Kill and logout an user
skill -KILL -u boo
Kill and logout ALL users
# skill -KILL -v /dev/pts/*
More information about it HEREhere.