This absolutely is. It's an illegal monopoly. It operates across state lines, which makes it Federal.
Monopolization, attempted monopolization, or conspiracy to monopolize can violate both civil and criminal law.
Monopolization does not violate constitutional law which is the Supreme law of the Land and is the ONLY source of valid federal gov’t action.
States operating under their state laws, fine. But the feds are bound and limited by only those powers enumerated by the Constitution, which gives the feds no power over monopolization.
A close look reveals the feds are behind any issues regarding monopolization. But in the market economy FREE from gov’t interference, “monopolization” normally doesn’t last too long.