This guy is so full of shit. All they can see is the public key and nothing else. Anything like Alpha Bay change the keys every few days so u can't track anything. All they have is a hexadecimal key which doesn't link to anything. RSA encryption cannot be broken because no computer can hash the prime numbers p and q so even if you have a public key without the corresponding private key u can't trace ur BTC to any website. If you're seriously paranoid u can tumble ur coins.