By safeguard I meant (and I think Amazon means too) an extra step that is required by the user before they can do the action so they don't do it by accident. Not something that prevents it entirely. Like how an MMO requires you before you delete a character to type the character's name in a box that pops up before you can delete it. That's far outside the realm of usual user interface, but that's so if you are just trying to edit a character it's impossible to accidentally hit that delete key. An analogous system for Amazon that would have prevented this outage: delete 10 nodes, ok. Delete 100 nodes, box pops up saying 'To delete this many nodes you must type the following in to a message box: "I want to take down a dangerously large amount of nodes."'