Re: Every time
been there, done that, I think I'm up to four people that I've provided evidence to HR for being naughty, and they got fired for violating company policies. (there were probably other factors, but that's far above my pay grade...)
We've had a few of the more brazen types trying to look at pron on the 'shared' machines we have in the employee canteen, obstinately for the purposes of being able to look up their benefits or use company related web sites while on their lunch break. Our security group has full visibility to the screens, and gee, the idiots got caught.