Solitaire Junkies

It has been reported to me (via a somewhat reliable source) that a couple of users are certified solitaire junkies. I am on an NT 4.0 network and would like to somehow monitor this.

Is there a way I can see when and for how long a user is playing solitaire? The ‘When’ part of my question is especially important to me b/c if it they play during breaks or lunch I don’t want to place any restrictions or uninstall the games.

Thank you