I’ve got from good sources that in Canada the RCMP is (...was several years ago) already doing exactly this. And it’s very easy to do since the exchange in question requires ID to create your account.
Sure. And so has the IRS, which “persuaded a federal judge”, according to the article.
I guess they thought it was a reasonable request to get the data of the 25,000 US citizens who made significant profit with bitcoin in those years, when only a few hundred reported such earnings in total.
It's not just a matter of tracking those that cashed out as taxes are on the net profits of individual trades. Even converting between coins (ex: sell BTC, buy ETH) is a taxable event.
The 4th amendment does not prevent combing through public data (the blockchain), nor does it prevent going through due process to obtain data (the coinbase order).
> store the history of all Bitcoin transactions
Bitcoin conveniently does this for them
> and try to identify all wallet owners
That’s the headline here
> check if profits were reported and if taxes were paid
Which is the IRS’ job