CEDA is a fictional organization by the US government. They appear in the video game Left for Dead. Also by Valve. They wear Hazmat suits and evacuate citizens. Everyone hates them. CEDA stands for Civil Emergency And Defense Agency. Geez I feel Like I'm writing a page now. For more Info involving CEDA visit this link: http://left4dead.wikia.com/wiki/CEDA . Thank you for you time.