Trust me, if you are on a network and accessing ANYTHING either inside the network or on the internet someone is watching you.
In our organization, every website that someone hits is screened. If you get a screen letting you know that you've been blocked it's too late - you've already been reported to IT and that is forwarded to your supervisor. All other traffic, if not blocked, is still logged as it is allowed into and out of the firewalls. Any IP address that shows up that is not "allowed" by us will be shut down immediately and sought out... Its not worth your job.