51% Attack with pools?

[ashaw596]

I'm not that us about the numbers, but I think that currently a couple mining pools control a large percentage of the bitcoin Hashrate. Would it be possible for a couple pools together to launch 51% attacks?

I'm not very sure about the technical details so. I'm asking a 2 part question. How much control do pool operators have over the miners and how large are the biggest pools?

[Spekko]

i dont see any way how a pool can cause the attack?, dont understand the question, but im sure if at all possible it will involve miners not getting payed out, and when that happens miners leave and pool loses hashrate

[RaTTuS]

http://blockchain.info/pools