A couple years back, a "high level employee" took a lot of confidential info with them, before they quit to work for a competitor. There was some big lawsuit eventually.
The result for the rank-and-file employees and our productivity has been kind of devastating. Word came down from high-level management that the IT/NetworkSec team(s) needed to install a bunch of stuff on all workstations (even developer workstations) to monitor everything. There are probably no less than about 20 things in my windows task manager for "Endpoint Protection" and "DLP Protection" and such. There's now whole-drive encryption. They force any removable storage device to be encrypted too, and anything copied off via removable storage will generate an email to your boss to "verify" that there was a "Business need" for copying those files to storage. They've forced man-in-the-middle certificates on all the browsers, so they have access to (and probably log/store) any online activity. Anything that causes a moderate level of disk i/o is frustratingly slow. Software builds that used to take 10 mins or so, can now take almost an hour. Machines lock up for seconds at a time when trying to do something simple like saving the document you are working on. It's a very frustrating productivity drain. It gets to me a lot... but every once in a while when this is happening, just slouch back in my seat and try to take solace in the fact that I'm getting paid anyway, even if my time is spent waiting for all the IT Spyware on my workstation to do whatever it wants to. I am way way less productive than I used to be. Some projects checked out from source control are on the order of 5-10GB in size. Those now take quite a long time to check out, due to all of the additional scanning/monitoring/"endpoint-protecting" software running constantly.
Since this started happening, I do absolutely ZERO personal stuff from the company computers and network. Any personal thing that comes up (needing to make a last minute bank transfer, deal with a personal urgent email, etc.) I do from my smart phone. I do not even use the corporate wifi for my phone... I use the cellular network exclusively, even though I pay per megabyte.