I think the movie The Blob was based on an incident in the Midwest where a truck carrying a load of Sno-Balls slid off an icy road releasing the entire truckload into the open. The cover story that it came from outerspace was just that.
You're right. We learned from that event that if you catch it early enough, and release pot-smokers into the area, you can contain the event, as they will gorge themselves on the cakes. The events in the Ukraine and Southern France were too far along for the pot-smoker solution.