How is this not a total death blow for bitcoin? If the justice department can do it, anyone can. It's a public ledger. So you effectively must treat every transaction you ever make on the blockchain as totally public and tied directly to you.
The DOJ always pats itself on the back to pretend to the worldwide audience that there is "no" illicit money in the US financial system.
They don't say "good thing they didn't use X method! that would have hampered our investigation irreparably!" at least not in press releases.
Justice must give the perception that they are doing enough. They can't really say that it's really hard to catch people committing crimes in cryptocurrencies.