I worked for a supermarket that underpaid their staff, timed checkout staff to see if they scanned fast enough, timed workers on clearing food deliveries, forced staff to stay late whenever they decided to do a stocktake, forced staff to clock out at 8pm yet made them do close downs which took around 20 minutes or longer.
As a response, I ate food out back and then wrote it off, gave customers free items by not scanning certain products, purposefully took too long on certain tasks just for the hell of it, and turned a blind eye to the shop lifters.
I managed to quit years back but I've never regretted for a moment punching back at those who exploit workers.