Well if no one will step up and do something we could be in for a rude awakening. Where are the bitcoin pirates with their DDOS botnets to take this pool down a notch 
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.... DDOS attackers are pure scum. Such an attack would cost other bit coin miners lost revenue. Are you going to pay them back?
I see few options if we actually reach 50%+ .... Bitcoins will be worthless if double spending occurs. Network compromised ruins this system.