It's very commonly used in insulation in the UK.

Are you sure people were being honest with you? Or were they trying to stop an inquisitive young person from grabbing a handfull of it?

That was asbestos, glass wool is reasonably safe to be around.

jup, just don't handling it sucks (it gets everywhere and itches if it penetrates your skin. construction workers often don't seem to give much of a * though...)

I used to work with ceramic wool and in big letters on the box it says that it's known to be a possible carcinogen. Not only does it kill you slowly, it hurts more than itches unlike regular insulation. The fibers are longer and sharper and really sting and take a few freezing cold showers to really get it out of your skin. I certainly don't miss those days :)