Out of curiousity, what's to legally stop one from flying a powered paraglider over a city? Town? Farmland? I'm sure there are resources I can refer to but having a hard time finding them.

I was terrified by a few things i saw at the landing area. Gliders were making super low turns (sub 200 feet) in a very crowed space right above the landing area; there were people landing in opposite directions at the same time; also many people were doing 360s and 540s without any obvious concern or checking around for other pilots. Is this typical for paragliding?