That they can "get away" with means demand. By increasing demand for the unit, for example by putting it under rent control, then landlords will be able to char

That they can "get away" with means demand. By increasing demand for the unit, for example by putting it under rent control, then landlords will be able to charge more. You are assuming that demand for the unit with rent control is the same as demand for the unit without rent control. This is why you think the rent control is "free" -- that it doesn't raise prices for tenants even though they think it's very important and are willing to pay more for such units.