Look at the antitrust lawsuits against printer manufacturers for ink refills. You don't have to have a monopoly in a sector (printers) to be subject to anti-trust laws, having a monopoly on consumables designed to work with your product can be sufficient.
Seems to me like the harmful to consumers aspect of the antitrust case will be the hard part to prove here. It seems like people are in near-universal agreement that printer companies were/are price-gouging on their inks in a way that is exclusively harmful to consumers. However, Apple's whole narrative on this TOS section is that doing otherwise would in the long run harm consumers by slowing down the evolution of the platform. Hard to see how the DOJ is going to prove otherwise.
Great, great point. The impact on the consumer is the bottom line for these laws. It's not the level of competition, how free the market should be, or how easy things are for developers.
The legal action that I'm aware of about printer ink alleges that HP colluded with Staples, paying them a huge amount of money, to prevent them from carrying a competing product.
But, as a counterexample, I'm not aware of a successful suit that challenged HP's use of printer cartridge rights management technology.
