The 1961 Sports Broadcasting Act was the first piece of gift-wrapped legislation, granting the leagues legal permission to conduct television-broadcast negotiations in a way that otherwise would have been price collusion. Then, in 1966, Congress enacted Public Law 89‑800, which broadened the limited antitrust exemptions of the 1961 law.
But in general, the teams make tons of money and have close zero profits. They use variations of "hollywood" accounting. Which might help explain the cognitive dissonance of profitless monopolies =D.
https://en.wikipedia.org/wiki/Sports_Broadcasting_Act_of_196...