I work in the office of a building contractor. We employ several builders, all of whom have company vans with trackers in. They're all aware of the trackers, but obviously this one's a bit forgetful!!! This happened a few months ago.
Let's call him Nick. On his timesheet, Nick had been claiming a little overtime every day for three months. No more than 30 minutes/1 hour per day. Fair enough, almost all of the builders work a few hours overtime per month (they can trade it in for extra holiday).
About a month before Christmas, the office manager called around to check who was taking holiday when. Nick cashed in his overtime for an extra three days off. Office manager tells the contract manager that Nick will be taking this holiday.
Contract manager: "Seriously? He's still got holiday allowance left?"
Office manager: "Well, no, but he's traded his overtime."
Contract manager: "What overtime?"
Yup. We checked his tracker, and he had been leaving site promptly at 4:30pm (their "end of day") every single day. Apparently he thought if he only claimed a little bit extra, we wouldn't notice!!!
Fortunately for him, our boss is a lovely man, and it was the month before Christmas, so all the punishment Nick got was a severe lecture, no Christmas bonus, no extra holiday, and his December paycheque docked by the amount of overtime he had already paid him. Next strike and he is out, though.