I don't believe them. I need proof before I am going to believe that President Kennedy was assassinated by the CIA or that the CIA was responsible for September 11 or that aliens are responsible for the disappearance of the Malaysian jet.
Nor do I think that there are rooms full of people reading everything everyone sends each other via the internet. I don't believe that the ordinary individual's mail is opened or that "the Tax Man" just has to ask to get all the details of your financial affairs and can then pass them on to a company specialising in credit checks.
There is a short video somewhere on the internet of a small "car" hovering and then apparently zipping around a Chinese city. The explanation given - that it works because of the special earth beneath the ground - is just this side of ridiculous. It is made to look convincing of course and it is a bit of good fun. There is another related video showing people how it is just a bit of nonsense.
Except that the Senior Cat and I know someone who firmly believes that it is not a hoax. He keeps pressing the video on people and telling them how dreadful it is that this technology is not being used and that, in the future, they won't be able to hide it. It will happen. I sometimes wonder whether he has managed to convince anyone else. Showing him the second video was hopeless - that was just part of the effort to make sure people did not believe it so that the big oil companies could go on fleecing people.
The problem with believing or not believing conspiracy theories is that there are other times when it is hard to know what to believe.
I had to do statistics for a year at university. It was a subject I loathed, not least because it was possible to manipulate things in ways I felt were dishonest and objectionable. Nevertheless the lecturer was an honourable man and, I sensed, he sometimes felt uncomfortable about the way the figures would be manipulated. He told us, "Get the facts. Do the sums. Apply common sense."
I'd like to think it worked but, somehow, life is not that simple.