Maybe, and I admit my knowledge of crypto has some holes in it, but I feel as if the Feds have ways to monitor things when they put their minds to it. No matter the currency form, at some point it's going to have to turn into dollars at this point. I doubt he could live off of crypto, and live off the grid. I'm not a complete conspiracy theorist, but, as with the big hack of the pipeline company the Feds got that money back. I think that unless you are an experienced criminal, they'd figure out a way to observe what you are doing.