There is actually a way around it, depending on the proggy. Some companies use a manager proggy to set the "keywords", the problem is getting a hold of those proggys, but I do know that there are some you can download it off of their websites for free, depending on the company and the proggy you use. I was just messing around with it last year at work, after they just installed it, and actually cracked it. The proggy was taken off of all the terminals in about a week, although I'm not sure if it was because of me, or because so few people access porn and gambling sites at work that it was not cost-efficent for my work place to subscribe to that service. Most of these proggys not only block your access to the restricted site, they report to the service company the web addy, which terminal was used, time, frequency....etc. Either way, I was glad that it was taken off.
But like I said, not all patrolling softwares have a manager proggy that you can download off their internet website.