Those people aren't "banned from having loud sex". They were banned from making noise in the night, while their neighbors are trying to sleep. Ana understood it like the government was telling them "how to have sex". That's just not true.

They can still have loud sex where nobody is disturbed by it. In the car, in the forest, in the dunes... Or they can have loud sex at daytime, maybe saturday afternoon. Or they can have more "silent" sex at night. It's just that they can't go ballistic, at home, at night, just like they can't play the trumpet or mow the lawn at night. The big bad government doesn't allow that either. Does that mean they're telling them which kind of instrument to play, or what their garden should look like? No, they're only protecting the bounds of reason.