I work with a few daily meth users, and a few friends are trying to subtly fuck with them do to the fact they are using a substance to be more productive than the rest of us. It's pure cheating. Where I work, production percentage is taken into consideration for raises.
A few things that a friend has done is misplace their keys, one has a hood that doesn't close, so fuses are taken out once and awhile to make them late for work.
I'm not a snitch so I am not going to HR, I just like watching them freak out when things go wrong.
Any advice would be great.