Let's talk conspiracy theories. There is an entertaining one out there. First, let me tell you what it is in a nutshell:
Wikipedia: The chemtrail conspiracy theory holds that some trails left by aircraft are actually chemical or biological agents deliberately sprayed at high altitudes for purposes undisclosed to the general public in clandestine programs directed by government officials.
Now, just for shits and giggles, let's look at contrails -
Wikipedia: Vapour trails are long thin artificial clouds that sometimes form behind aircraft. Their formation is most often triggered by the water vapour in the exhaust of aircraft engines, but can also be triggered by the changes in air pressure in wingtip vortices or in the air over the entire wing surface. Like all clouds, contrails are made of water, in the form of a suspension of billions of liquid droplets or ice crystals. Depending on the temperature and humidity at the altitude the contrail forms, they may be visible for only a few seconds or minutes, or may persist for hours and spread to be several miles wide.
Okay, now you vote -