Im not one for scaremongering  but I read an article on http://bitcoinist.com/bitmain-51-percent-bitcoin-hashrate/
titled "Bitmain Approaching 51% of Total Bitcoin Network Hashrate".

Now we all know the dangers of the 51% and too much control and
I wasnt aware bitmain had such a big slice bitcoin mining are they
really a threat to the 51% capacity and is it something to be concerned
about?

Also would it be the case that if they got closer to that figure smaller
miners in the pool would move to another?