Except that this was not 'tossing a brick,' it was maybe knocking on a window to see what sound it makes, and the window then falling apart for no apparent reas

Except that this was not 'tossing a brick,' it was maybe knocking on a window to see what sound it makes, and the window then falling apart for no apparent reason. There is nobody to blame for this, actually. Neither could the kid have known that this was bad (and the child-like curiosity is hardly something worth a punishment,) nor could the sysadmin really do anything to prevent it, except hang up a memo: please don't do that. Though, in that case, you'd have some kids doing that over and over again out of a very different kind of curiosity.