At my work, if they are warranty we tag them and hold onto them. If over certain mileage; me and one of the other mechanics take them to scrap yard. We had a fat, lazy homeless looking dumpster fire of a “person” that always looked for catalytic converters and batteries. I started keeping a baseball bat under my 20+ year old craftsman toolbox as some were warranty. He hasn’t been back in a while since he got busted for not having a PA drivers license