I think it's referring to the fact that you pay to a hash of a public key, but once you do a singe transaction, the public key becomes known. I'm not sure how

I think it's referring to the fact that you pay to a hash of a public key, but once you do a singe transaction, the public key becomes known. I'm not sure how that's a vulnerability, since the leftover balance is paid to a new address, and I was under the impression that early bicoins were paid to public address, and pay-to-hash-of-public-address was added later. I'd love for someone to enlighten this. (I got out of bitcoin when TradeHill was still running).