... and we don't need those pointless expensive safety rails on bridges, just let people walk off the edge if they want to.
The point is (or is supposed to be) that you can purposefully jump the safety rail if you want to, but it is meant to be unlikely that you'll do it by accident when casually walking along in a daydream.
Quite long time ago but didn't change my mind in general.
If there is a rail on the bridge, I can SEE that rail easily. It's not a hidden wall where I possibly ram my head on. The programs executed in a sandbox could be marked in a manner where I can notice those applications. Could be another (maybe red) color in the title bar, a special optical mark in the task bar or whatever.