The FCC has already taken action, in 2004, by formulating a set of principles based on Net Neutrality, and later by making those principles part of their policy statement in 2005.

They've even levied fines against carriers who do not adhere to these principles.

Thus, there is already government regulation, of sorts, and an additional Congressional Law would be redundant and ultimately harmful, as it would no doubt provide no governance, or means of enforcement, funding for oversite/enforcement, and so on.