You should say "a conspiracy theory" or "conspiracy theories" in the title. Have you ever heard of the Ides of March? Those who don't believe any conspiracy can happen are ignorant of life and history. If you think several planes were hijacked simultaneously and then sent to attack several buildings had some kind of planning behind it then you believe in a conspiracy.
Thanks for your tip @leprechaun... Look, many things that happen are really strange, for example simpsons, how can he predict in advance what will happen and does it really happen?