There's also "Put your hands where I can see them, you are under arrest for committing illegal financial acts". At the end of the day, the government has sovereignty over your physical body.

In addition, at some point your virtual money has to be turned into something physical or else what's the point? And those physical goods can be monitored and irregularities can prompt questions.

Actual shares, no. A crypto bucket shop will show up in the short term, I can guarantee it.