Agreed, sometimes the reward is just too high to simply "pass on an opportunity".

We had an undergrad utilize our then, nascent CUDA nodes. But, simple monitoring of the nodes raised a red flag.

When we looked into his running jobs, we found an expediently crafted work-flow, where there was no attempt at obfuscation. That is, the user's input files all contained references to various mining sites at that time...

Needless to say, privileges were revoked and never restored!