I've worked in IT for 20 years for a variety of companies, from small to large corporate environments.
And in that time, I've never been requested to spy on any employee ever. If an IT guy is asked to do that, there is something fishy going on, maybe something illegal (that the employee is doing).
BUT--as anyone with admin power knows, they can record, find, and do anything they want. I can see any web site they visit, completely monitor every single email, see every printed document--basically anything. And if for whatever reason me, or any IT staff wanted to, we could monitor keystrokes or take screen shots or install monitoring software.
This includes any data or activities on company provided cell phones.
There's nothing that an employee does at work that can't be found out by the IT guy. That's just the reality of it.
But here's the thing--it all sounds like we have a lot of power---and true, we do. But the truth is--we don't care!
I have much, much better things to do than to monitor what websites people go to, or look at print queues, or spy on what people do on their lunch break. If the IT guys working for me had some creepy inclinations to spy on co-workers, I would replace them.
The bottom line is this: just because we can do it, it doesn't mean we're remotely interested in doing it, or that it is time well spent. It's just a waste of time, in virtually all cases.
The only FUNCTIONAL use I have found by having admin power to see what people are up to--is to see who is printing out 20,000 color pages/month for personal reasons, or on occasion, who is attempting to put pirated software on their PC's, or consuming copious amounts of bandwidth.
Apart from that, if your employees are doing such nefarious things that require professional spying to divine the nature of such deeds---then it's probably time for a new employee.
Anecdotally--there was this one time that we had suspicions that our after hours contracted security staff was eating lots of food from our company kitchen, so I setup a laptop in the kitchen, disguised as a carboard box, and installed some motion sensing software--and sure enough! There was this big ass security guy who would come in each night and completely gorge himself on the food in the kitchen. He'd then pack up some beers and sodas and head home 😀
Anywho! On topic: anyone who has been in the trenches in IT would probably say the same: we've got better ways to spend our time.