"Right click on the user Click Details... to open the Peer Properties dialog Click on the Settings tab Click the change... link to set the Traffic settings for this user to Block All
Now you have cut them off from your network, i.e. ""banned"" them. To let them back in, just set the traffic setting back to one of the other three settings based upon your security preferences (Block unsecured, Block untrusted, or Allow all)."
