Thats what they may want, thats not what their going to get. Crypto is just too big, the people will not stand for it. Not to mention the hedgefunds, and businesses buying into it. Right now I know of no US legal exchanges that allow you to buy and sell without a valid photo ID, so thats already there. Also on my taxes this year I had a box to report gains in crypto as well. Not to mention how much potential crypto the feds have in their possession. They have what 50 million from the silk road guys account alone and that was prices back in like 2012. Crypto is just to big, and established, and being decentralized lends itself very well to under the table transactions and useage.

And like all things banned, or restricted, people will always find away.