I have 7 subordinates who work in our Office Branches, who use our official PC but sometimes they watch movies or some adult stuff during office hours which is not permitted by Rule. I installed teamviewer to those PCs as well as mine (via high speed internet) but when I get connected, firstly, they can notice while I'm connected as there are some activity appears in their PC, secondly while I move my mouse, their mouse pointer also moves so they become alert. But employee with serious offense like watching adult film, they become used to that symptom, become alert and promptly hide content easily. I tried freezing their mouse movement or blanking screen, that time they think PC has hung so, they restart the PC. So that's not useful most of the time, as monitoring their activity.