Not all conspiracy theories are as ridiculous as the Flat Earth movement.
The people of Reddit put together a thread on plausible conspiracy theories that have more evidence, reason and logic on their side than the usual crackpot conjecture.
1. Was the TSA intended to just give the illusion of safety?
Created after 9/11, the TSA (Transport Security Administration) dramatically increased the number and invasiveness of airport security checks in the US.
Yet the TSA is wildly inefficient: Homeland Security officials pretending to be terrorists managed to smuggle guns and bombs onto planes 67 times out of 70.
All this has left some speculating that the organisation is just for show.
2. Don't trust Twitter and Facebook? Maybe you should add Reddit to the list.
3. A few think that Snapchat filters might not just be for fun.
However, fact-checking site Snopes called this one out as totally false.
4. Cosmopolitan sex and dating tips are weird for a reason.
6. If your phone is short-lived, ask yourself why.
It sounds both manipulative and macabre, but some are convinced that phones are designed to die.
It might not be such a crackpot theory, with University of Sydney media professor Gerad Goggin telling ABC News:
It's a concept that has been obvious for a long time in terms of a consumer society.
And there's a sense now in which the built-in obsolescence in devices is shorter than usual.
Goggin believes the tactic allows manufacturers to flog another product.
6. There's even a conspiracy theory about the danger of sharing conspiracy theories on the internet.
After the US military researched how to influence social media users, some are twitchy that the government are using threads like these to work out how close to the truth we are.