Usage: LUSERS <server name>

Displays information about the number of users currently logged on to your server and the network. If you leave the server field blank, it will return with the current server you are logged into. If you use it with a * it will get the lusers information from the target server. If you designate a target server with no asterisk than it will return the number of users that your server shows at the current time.

/lusers webmaster.*