[jsprogrammer]

Exchanges are peripheral noise.

What would 'banning bitcoin' even mean? All that is required is the computation of a number and its transmission to the blockchain. It's impossible to block such a message without blocking all other communications.

[lotharbot]

likely, "banning bitcoin" would take the form of barring companies from accepting it. It definitely changes the value proposition if Amazon, Target, Overstock, Subway, TigerDirect, Home Depot, etc. can no longer accept bitcoin as payment. There's no need to mess with the blockchain if you can simply eliminate mainstream use and force it onto black markets.

[jsprogrammer]

On what basis could a company be banned from accepting it? No physical items are exchanged. It's simply a record in a long chain of integers.

[dragonwriter]

> On what basis could a company be banned from accepting it?

If by basis you mean authority, the Commerce Clause is most likely, though I suppose the Coinage Clause might be invoked as well.

If by basis you mean policy motivation, there's an infinite number of possibilities.

> No physical items are exchanged.

Government regulates acts that don't involve an exchange of "physical items", but just electronic data, all the time (pretty much all instance of wire fraud, CFAA violations, among many examples.)

[jsprogrammer]

I mean basis as, what technological basis would disallow the transmission of Bitcoin transactions, but still allow all other digital communications?

[dragonwriter]

Most government prohibitions don't involve technological barriers. (E.g., the prohibition on murder doesn't involve the existence of technological means which obstruct homicidal acts but not other human interaction.)

[lotharbot]

Engineers like to use lines like "long chain of numbers", but that doesn't really hold weight. Stolen credit card numbers, digitized child porn, and terrorist communications all also qualify as "just a bunch of numbers". So does the majority of NSA surveillance, which most HN'ers oppose.

The government is pretty good at figuring out justifications for banning things. I wouldn't rely on reasoning as flimsy as "it's just numbers" for why it couldn't happen. (I'm not saying I expect them to, just that if they did, it'd most likely take the form of a merchant ban, "just numbers" would not be an adequate justification, and all the big retailers would comply because none of them want to risk a big legal fight.)

[jsprogrammer]

>Stolen credit card numbers, digitized child porn, and terrorist communications all also qualify as "just a bunch of numbers".

Sorry, are you claiming that government has stopped those things?

A government can say whatever it likes. Actually causing that to be reality is a much different problem.

[lotharbot]

I'm claiming that those things are less ubiquitous than they'd be if they were legal. You can get them, but you have to do so underground, and there are risks associated with that trade.

You seem to be thinking in terms of whether the government has the absolute power to 100% stop something. The rest of us are thinking in terms of whether, if the government declared something to be illegal, it would have a significant impact on that market. I claim that it would. Part of the value of bitcoin is that you can exchange it for physical goods at major retailers like Home Depot, Target, Subway, and TigerDirect. If the government declares a ban, those retailers would almost definitely honor that ban, and then bitcoin would become less valuable overnight.

[s73v3r]

They couldn't accept it as payment. And it is that simple.

[dragonwriter]

> What would 'banning bitcoin' even mean? All that is required is the computation of a number and its transmission to the blockchain. It's impossible to block such a message without blocking all other communications.

Government prohibition of an act rarely involves blocking all instances of the act (in fact, if the government could effectively make an act impossible, it wouldn't need to prohibit it.)

So the question here just seems to miss the entire idea of legal prohibitions.