> Is there some law that forbids this? Yes. It's called the Sherman Act, and it's the basis of anti-trust enforcement in the US. https://www.ftc.gov/advice-gu

> Is there some law that forbids this? Yes. It's called the Sherman Act, and it's the basis of anti-trust enforcement in the US. https://www.ftc.gov/advice-guidance/competition-guidance/guide-antitrust-laws/antitrust-laws https://www.ftc.gov/advice-guidance/competition-guidance/gui... <<<The Sherman Act outlaws "every contract, combination, or conspiracy in restraint of trade," and any "monopolization, attempted monopolization, or conspiracy or combination to monopolize." >>> I know lots of people here don't like it, but it is the law and that was the question; "this" in parent clearly meant "use dominance in one market to gain dominance in another" in grandparent, regardless of whether that's actually the central issue here or not.