I've met many internet strangers before, and I've never had an experience like that bbefore. That said, I also generally meet strangers in public places, so nothing happens.
Good rule of thumb for any meeting where you might end up in a non-public space.
If you're just doing a buy/sell thing, you can count on doing the entire exchange in a public space. If you're meeting someone for a date, you might end up in a more secluded setting. It doesn't happen as much around where I live, but I've read stories of it happening in other parts of the world