One can hold that under a limited, federal government structure there are things the Federal government must not do (because it is either explicitly barred from it or it is not one of its explicitly enumerated powers), and that the same constraint applies to the States.
For instance, under the US constitution, freedom of expression limits all levels of government.
I liked the above comment and wanted to tack on my reply to jonwachob91 here.
There are some cases where affirmative rights granted to the federal government also limits the power of the states.
For example, the Supreme Court found in Gibbons v. Ogden (1824) that not only does Congress have the right to regulate interstate commerce, but only Congress does, and that States can't create their own rules for commerce between each other.
(The FCC can claim they don't have the right to enforce Title 2, but that's really for the Supreme Court to decide.)
I think it's worth noting that Title 2 classification is not Net Neutrality, and that the Title 2 classification was based off of an idea of 'forbearance', that the government has granted itself broad sweeping regulatory powers over telecoms but promises not to use a lot of them (rate setting, etc).
Title 2 classification had a lot of problems, and real Net Neutrality legislation is preferable.
This seems so concrete-bound... Moving to the conceptual level, since the initial F in each agency name stands for "Federal" -- in what sense are they not part of the Federal government? are they somehow not subject to the limits imposed by the Constitution?
For instance, under the US constitution, freedom of expression limits all levels of government.