All places I have worked, since about 1990, were monitoring computer traffic.
Several people were fired, because they accessed on-line pornography!
Justification was always - these are company computers, you leave your privacy at the door!
Sure makes sense to me. I do think that signing a document listing conditions of employment, other than dismissal for felony or misdemeanor conviction, should be part of accepting the offer
I felt like I was going to get fired for listening to Rush Limbaugh on stream from my work computer...