ostracism of any >40% pool operator is the best regulating mechanism IMO
Also not being a stupid fool and thinking that being with the biggest pool somehow increasing your mining income helps too.
Also support smaller pools, I do.
mmmph. you are
a smaller pool...
but seriously, the previous post has some truth:
Right now the danger exists because pools are a relatively new idea and all the early adopters have chosen their favorite. As the number of pools grow, I think the chances of one pool getting >50% goes down...
although in fairness i think that whole +50% thing is way overblown. i can't really imagine anyone motivated by money trying to double-spend, rather than using all that hashing power to just mine. someone motivated by something other than money may give it a shot, i suppose - but the blockchain is likely to shrug it off.
we have the most powerful network on the planet at this point. and we don't look likely to lose that.