Very interesting information. The article itself states that, unlike such coins as EOS and ripple, the specific addresses of BTC and BCH cannot be blocked even by the all-powerful US government. Bitcoins come and go to two specific BTC addresses, and the US government can’t stop it. On the one hand, this is good, as it proves Bitcoin’s invulnerability for outside intervention. However, in this case, the United States can go further and prohibit the general circulation of Bitcoin in its own country.
Anyone can blacklist any address if they are willing to commit a 51% attack for it, but it will be noticed pretty quickly.
While cryptocurrency exchanges can and do block accounts linked to certain addresses, the Bitcoin protocol remains immune from such interference.
Exchanges freeze accounts on a regular basis. That's all this is about. The government isn't trying to interfere with the protocol. OFAC is just telling exchanges and money transmitters to confiscate funds under their control that are tainted by those addresses. This isn't so different from OFAC publishing name identifiers so that banks know to block associated funds.
I'm curious, how much taint is required to trigger that response. I've heard that pretty much every Bitcoin is tainted by the Silk Road, just like most of the US dollars have traces of cocaine on them. Such regulations can be really bad for exchanges.
