Most persons had continually have that notion that Bitcoin transactions are completely untraceable to the point where they finally spend it, but little do they know that this transactions can be followed up till they get tracked but mixers at a time did looked like they were going to come in the way of such tracking and tracing but I honestly do not know if they really do enough to not gwt any track able trace of the coin but if such coin is rather snet to an exchange that requires KYC , the chances continually remains high to trace the source and known the senders of the bitcoin.
With the government, there are some many possibilities that we may not be aware of which we not been aware of such is a security measure and that is why they are known only by the government and a few others so the tracing of Bitcoin and all of that is what the government can achieve, they have what it take and all the tools they .aye be needing to carry that out actually.
That is common mistake is thinking Bitcoin is untraceable but every transaction is publicly recorded on blockchain which allows for tracking. But mixers were once which use to hide transactions but new tracing tools can mostly figure them out so they are not perfect way to stay anonymous. Also sending Bitcoin to exchange that asks for your personal information makes it much easier for authorities to connect your real identity to transactions. So governments have special tools and resources that give them big advantage in tracing digital money and fighting financial crimes.