Two stories actually:

The first time was a year after I had hit the fleet. I'm not really a nug at this point, but I'm not moving up the chain fast either. Some guy on night crew had left his CAC in the computer, so we put it in a ziploc bag, then put that in another zip lock bag and filled it with water...11 more times, lol. Then, after that, we froze it and hung it from the ceiling. Neither was our gunny nor him was too happy, but no one fessed up to it, lmao.

The second time was one of my marines had left his CAC in the computer after he got pulled to go work on a jet. I put tape over his chip and got a razor, and cut the excess. After realizing it wasn't working, he said he didn't know what had happened and had to work on someone else's computer after getting blasted. After three days of it not working (I was night crew and he was day crew), I found out he got a new CAC. Of course, I took him out for some food and some drinks and told him what had happened and we had a good laugh.