No, but I have checked uptime on a system to know that a user was lying about having rebooted before calling.
One of my best calls was someone whose monitor said, "No signal". I asked them if the computer was turned on, they said, "Yes."
Me - Can you check to make sure the cables are plugged firmly in to both the monitor and the computer?
User - They are plugged in
Me - can you double check both ends of the cables, both to the monitor AND the computer?
User - what do you mean?
Me - check to make sure that the cables are plugged into the monitor, and to the box under your desk.
User - There is no box under my desk.
There was no computer at the desk they were using. Just a monitor.