Throughout both series, we were presented with several ways of imprisoning water benders, fire bender and earth benders, from gigantic complexes such as the Boiling Rock to portable cells (i.e. the metal cells they carried Toph once, before she could metalbend).
But my question is, how do you set up a prison, in a large scale, or in a permanent state, for an air bender or a group of air benders?
I know air benders are presented to us as the most peaceful ones, being monks, etc., but I find it hard to believe that inside their society they didn't have criminals or people that needed to be imprisoned. So how would they go about it?
PS: I tried looking for a question like this and didn't find it. Please let me know if this is a duplicate.