I am planting crypto tulip bulbs on my virtual land where I live with my virtual family and spend my cryptocurrency. And I lived happily ever after until the power got cut and reality intruded.

The government can easily pull the plug on any cryptocurrency, then its lights out. Also the exchanges are frequently hacked. The chances of that happening to stocks portfolios or money in the bank are not zero but significantly lower. So much for the hard core thinking types.

The same way they track illegal financial transactions, child pornography, terrorism or any other nefarious activity on the internet. If it happens on the internet, the government can track it, block it and figure out the origin and target of the data package. The NSA employs over 20000 people and has essentially unlimited funds. Any activity that happens outside the internet becomes much harder to track, but the nature of any crypto-currency is that the transactions happen on the internet.