It's not an ethical dilemma for me. It's the same as going long - buying something and placing a bet that it will soon increase in value. How is shorting worse than going long? It just feels unnatural to me.
Another way to look at it, if you are shorting Bitcoin against USD, then your are going long on USD against Bitcoin and vice versa so it is essentially the same ethical barrier to break either way.
RE: Bitcoin Bubble Burst !!!