IDLE USER Defeat Program?

Leslie Bester (les@icenter.net)
Tue, 4 Jun 1996 11:39:13 -0500

I came in this morning to find a user logged on for 9 consecutive hours (no real big deal) but his idle time would never go above 1 minute.
I stared at the modem lights for 5 mins and noticed a frequent pattern of blinking about once a minute.
it doesn't appear to be a mail-check, or atleast, not on my pop3 server...
Is there anyway to check what type of data this user is sending by monitoring his session somehow?