Re: 51% attack possible ?

A government attack is a significant risk. Think about China: they have the resources to pull off the heinous deed.

I should apply XKCD's famous "$5 wretch" argument here: if an authoritarian government wants to screw you, there are much easier ways to do it than a 51% attack, otherwise if they want to play, they would be very careful to not tip the balance.

Like what?

Shutdown ASICMiner and Avalon, arrest everyone and scare the daylight out of all the remaining Chinese miners.

That's far from the destruction of Bitcoin. They can do what they want in China, but not the rest of the world.