[stryan]

> And are Hindu or Christian meditation practices dangerous, or just the secular stuff? What precisely is the nature of this danger?

I don't think the argument is usually "meditation without Buddhism is dangerous" but rather "meditation techniques taken from their context can be dangerous". Regular mindfulness or insight meditation can cause shifts in mental state that a person isn't used to and they may not have the tools required to deal with it in a healthy manner.

It's like the mental equivalent of a normal person suddenly starting the same workout routine as an professional athlete, or even just an experienced weightlifter. They might be able to do the exercises, but they don't have the context provided by having a coach/being in the sport/etc to provide them with tools like "how to fall properly" or "knowing a torn muscle versus a normal sprain". That doesn't mean that doing the exercises in general are bad or that you need to do sport foo in order to exercise.