All of their transactions are visible in the ledger, not hard to find. The same tools they used still exist today, except with additional privacy enhancements like some chains using zk-SNARKs.
The only weak points are exchanges. The OP can decide how anonymous they want to be - complete anonymity would imply not exchanging to fiat at all.
The only weak points are exchanges. The OP can decide how anonymous they want to be - complete anonymity would imply not exchanging to fiat at all.