Peaceful?

I took this picture on the way to work this morning. I must say I am quite impressed with myself. I am becoming quite the photographer.

So while most of the world was rat racing to work , these two lucky indiviuals were floating peacefully and silently above it all, oblivious.

...I say it must be peaceful but I'm not sure how peaceful it would be with me screaming bloody murder. Are these things really SAFE??