I experienced the same thing!
I laughed at the idea at first, then saw them actually doing it.
I saw three planes, 2 had contrails, and 1 had a contrail at first, then just as it flew over Toronto the contrails turned into chemtrails. The chemtrails were not continuous, it was in patches, like someone was turning the sprayer on and off. As the plane left the city limits the spraying stopped and it was back to a normal contrail.
I wonder what they are spraying? I've heard its Barium and a few other nasties...
Not enough to be immediately toxic, but a constant low dose.