the more processing power the network has, the more processing power an attacker would need to overpower it. ASICs are so much faster, cheaper and more efficient then what came before. the network is far stronger then it was before. Nobody can develop an "ASIC" and easily blow away our network because we already have ASICs, if we were still using CPU's then any entity out there could have developed as ASIC and overpowered the network easily.
Ok, what about PoS coins.
You don't need no ASICs there, check out NXT.
NXT doesn't need any mining power in hardware, and that's the beauty of it.
You can't destroy NXT network, unless you buy all the coins in existance
