There ARE thousands of BS conspiracy theories. That's why it's necessary to use discretion when deciding which ones might be true.
Chem-trails, for instance, are nonsense. The physics behind CONTRAILS is well understood, and planes definitely create them as they pass through air of the right humidity and temperature. (When there is a pressure drop, as created by a plane's wing, the air can no longer hold as much moisture and it precipitates out in the form of a cloud.) I once spent an hour watching small clouds forming and dissipating off of a rocky peak as I backpacked in Yosemite. It was a really cool and completely natural phenomenon.
But if that's not good enough, consider this. If chemtrails are, in fact, made of hazardous chemicals, why has no one flown a small plane pulling a sampling device through one of these chemtrails in order to determine what they contain? It would be a simple thing - hundreds of thousands of private pilots could do it if they wanted. But for all the fuss about chemtails, not a soul has thought to take some samples and prove their conspiracy theory to be true? I find that hard to believe. Impossible to believe, in fact. Why wouldn't they have done it?? The only possible answer is because it ISN'T true. Those who've tried sampling the chemtrail have come up blank.