Court rulings in the past
it's the company's equipment, they're responsible for anything you may do on it, they have the right to access everything you do on it including but not limited to web browsing, email, shopping, etc. Now I don't know if there has been a trial case of accessing a computer web cam and physically watching you, not your computer work or not. Cameras are used, but I'm not sure about that use would necessarily be included. That might be considered unknown survillance and possibly have some legal grey areas.
I'll grant your IT guy monitoring live time all the time would be rather unusual, and even creepy, but as long as he does it in connection with his job, it's legal. However, if the IT guy used any information gathered that way other than reporting problems to HR, his ass is the one that should and could be in a sling.