What is to stop anyone in the world from creating alternatives to Bitcoin? Clearly, it doesn't require asset-backing. So why is it special?

Personally, I think competition is coming, and it's coming hard. But I also think this is going to be great for the *concept* of BTC. The biggest threat to private currencies is government intervention. The more private currencies that compete globally, the more difficulty governments will have shutting them down. Once private currencies become established, governments will have to become competitive [sic].

So what would stop anyone from starting his own version of BTC?

Mack