How low can a plane fly legally over a residential or highly populated area?
In general the aircraft must be at least 500 feet away from any person, vessel, vehicle, or structure. In congested areas the aircraft must stay 1000 feet above the highest obstacle within a 2000 foot radius of the aircraft. There are special rules for helicopters that allow them to fly closer than these general limits. There are some exceptions when aircraft are taking off and landing, however.
