Are you joking, or are you really that stupid?
Contrails are completely understood.... Condensation from jet exhaust... Condensation trails=Contrails...
Why are they over populated areas? Well... lots of airports happen to be mear populated areas for some strange reason.... Planes seem to be statistically crrelated with airports...(isn't that odd?) ergo planes and populated areas seem to be correlated.
As for the quick dismissal, well it is because to claim they are anything more than condensation trails is lunacy, lunacy that has been FULLY debunked. NOT ONE THING indicates there is anything at all mysterious.
You know, I don't expect everyone to think critically all the time, but to see through this stupidity requires only that you think...