This week, American diplomats took down the State Department's email system by using reply-to-all. They're not the only ones to make this gaffe. Spirit Airlines' CEO hit reply-to-all in response to a customer complaint. A corporate attorney sent a note intended for a client to a NY Times reporter. A Minnesota judicial candidate replies to an email claiming Barack Obama is a Muslim. Maybe they should read this guide to knowing when not to reply-to-all. Or their admins should prevent them from using reply-to-all or forward in Outlook. Also, don't put everyone's addresses in the TO: field - Seagate Software, AT&T, and Nissan found this out the hard way.