Because if you attempt to influence the state of the entangled bits--say, to set a bit to up/down (dot/dash or zero/one) state to form your message--you will br

Because if you attempt to influence the state of the entangled bits--say, to set a bit to up/down (dot/dash or zero/one) state to form your message--you will break the entanglement. You can measure the states of the unperturbed entangled bits, and therefore know about the states of their distant entangled partners, but the message will be random. You could also influence the states of the bits while you create the entangled pairs, but then you have to carry them far away from one another (at less than the speed of light), so you won't be able to communicate FTL; you would just have a pair of messages in a bottle, so to speak.