A large mosquito net laid out in a circus-tent like form would work quite well. Plus now you can prevent the people inside from getting sick via mosquito-borne illnesses. Make it out of metal to resist the drones from just cutting the net open, with the added bonus that you just created a Faraday cage so that only approved and cleared cell phones can be used inside (using a femto-cell like arrangement inside that filters which phones can get out).
Biting the hand that feeds IT
