However they can take over the system by having control over more bad bitcoin nodes then good ones.

Once that happens they can do some pretty crafty (&shady) shit. Easiest way to put it is duping..they'd send coins to someone (most likely large amounts such as cashing out their hundreds or probably thousands of bitcoins..get the cash, then automatically the coins will be reversed and go back to the original sender...why? cause he who controls the nodes, he hath control of zee system!

If that were the case...watch yo back...