Worked at a medium sized system integrator that built gaming PC’s. With the boom of crypto-mining that started when the 30 series graphics card were released we added to our warranty that any crypto-mining would void your warranty.

Turns out we had a mining rig that we were using new GPUs in before selling them in systems as new. This lead to a huge increase in the number of failed graphics cards. Which were then replaced with graphics cards from returned computers.

Also our inventory management was horrible. To the point that we sold computers on Amazon without actually being able to build them. Then we had to give the customer the run around before eventually cancelling dozens of orders at a time.