Not exactly this, but you can easily make big sparks and trip RCD (GFCI) breakers if you accidentally probe something with a grounded scope that isn't isolated.

Not exactly this, but you can easily make big sparks and trip RCD (GFCI) breakers if you accidentally probe something with a grounded scope that isn't isolated. In the past we've used battery powered scopes to get around this (cutting the ground pin off anything isn't a good way to do things!)