[sorbus]

> If people want what Bitcoin provides.

That's the key point. There is a huge demand for alcohol, for drugs, and for cheap/free content. In the first two cases, this means that there is real profit to be had in selling it, and the illegality means that prices can be hugely inflated due to risk. For free content - "car downloaders" is a really nice way to describe it - I haven't yet figured out the economic motives, but it seems to be a mixture of selling ads (for the people running the sites), sharing/giving back to the community (especially on private, invitation-only trackers), and just because of how easy it is.

Is it possible to make money or karma off of bitcoins in a similar way? Well, you can sell them. If you have bitcoins, you can make a profit of them that way - you can sell them for above value, or charge for the service as well as the coins. You can also buy them, hoping that the price increases, which ends up as selling them.

So, answer this: if bitcoins were made illegal, what monetary incentive would there be to use them? Their price certainly wouldn't go up - it would plummet as all the legitimate traders tried to get out.