Years ago when i was office based i was, I spent far too much time on a car forum and got a rollocking and the web admin then blocked all web forums, facebook, social media etc etc for the whole company!
I think today, no one cares what i do as long as i hit target.
Yep. In my last job I said I was bored and I work better taking lots of short breaks than working constantly. They checked my figures and I was the best in the team and so agreed though they did ask me to be slightly smarter (leave pages open rather than refreshing, so it looks like less visits to webpages).
So far so good in this job but I'm the boss in this office so they'd need some cajones to report me.
I'm the IT admin of the place I work and I don't block any of this stuff. Nor do I dob in anyone I see on forums. Although I did block one football forum last week because it had trojans on it. Everyone that went on it ended up infected with things being cleaned up automatically.
Still don't browse around for ages though. Usually in and out between doing desk work.