Trancendental Meditation dangerous?

I came across this website:

Falling Down the TM Rabbit Hole, How TM Really Works, a Critical Opinion

It is saying that trancendental meditation can have negative psychological effects. Has anyone read about this before? Is there any validity to it?

 

You give me a topic and I'll find someone who disagrees with it, or who says it's dangerous.
Moral of the story, don't believe everything you read.

More true, is the fact that any meditation, or indeed any practice of any sort, complementary or otherwise, can change how we perceive things, and in a lot of cases, that can mean that 'negative' things we're holding onto can arise. Often that should be perceived as something that is expected, and a good thing, because it gives us the opportunity to deal with things and move on. However, sometimes people have deep rooted issues that could require some more serious help to get through, and it's often these people who need to be more careful, and often these people who start shouting about how dangerous such practices are, when really the issue is within them.