When I was laid off security walked me from a conference room near the exit to my car. I was not even allowed to collect my stuff from my desk, had to have a friend bring it to me after.
This happened to my boss, the IT manager at a law firm, when he was fired. Part of his firing was due to complaints by the IT staff, the rest for other reasons. I deactivated his account while he was at lunch, his staff -- three of us, as I remember -- were told to leave for the day, and he was escorted out when he returned from lunch.