[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.