Define "maintain". If you mean "pay the guy who installed it to keep it in good working order", there's no problem. But if you mean "pay the guy who installed it to record everything that comes off the antenna then set up a commercial service to redistribute that content anywhere in the world to a device of your choosing" then it's a probably illegal. On an individual basis it's also pretty inconsequential, so as a practical matter, it's not a concern.

But if you were the owner of a big enough building and were also charging people for the wire service to their apartments - and beyond - it gets more problematic. Indeed, a variation on this is what the Supreme Court ruled against decades ago. And if you do this on a truly industrial-sized basis (as Aero did) then expect the hammer to drop.

I reckon you wouldn't be able to have your own antenna in your New York apartment, unless you actually own the apartment. Renters are out of luck.

They're only out of luck if the owner refuses to install an antenna. But assuming that an antenna exists and that it sends connections to each apartment, then they're back in luck.

If the owner amortizes the cost of this antenna as a general building expense, and sets all the rents accordingly, there's still no problem. However, if the owner attempts to charge a separate fee for that connection (or tries to raise the rent for people who opt out of paying that fee) then he has not only inserted himself in the middle of the content transmission stream, he has done so on an individualized commercial basis. In effect, he's made himself a micro-distributer by establishing a cash for content deal with his tenants and the law has a major problem with that.