Even a federal law may be wrong. Thus it must be possible to challenge federal laws. Sometimes citizens do that and it's called civil disobedience, for which there is sometimes administered punishment and sometimes not.

The Bundys challenged the concept of the Federal government reserving the rights to decide over the state of Nevada over it's land use. On the path to decision making it came to a temporary decisive moment when the feds where asked the question, "do you really want to initiate violence over this at this point?" Wisely the feds answered no and stepped down.
The matter is now handled more peacefully in courts. Everybody should rejoice.

Cowardly men always plot to label Freedom as anarchy!