And the exception use case could be handled the same way that Flash was during its decline -- a box showing that there is some special content on the page, but

And the exception use case could be handled the same way that Flash was during its decline -- a box showing that there is some special content on the page, but it doesn't run until you explicitly click on it. Then it's there when you need it, but the friction discourages it from being used frivolously and gives you the opportunity to decline when the context makes it obvious it's not being used for anything good.