
Before hitting "Reply All" think about who really needs to see your response. Please take 10 seconds to considerately think about your friends and colleagues. Do they really need to see your response? Will it change their life for the better? Will it save them time or money? Is there anything they can or should do about the content of the email?
If the building is in fire, hit reply all. If your company is at risk of imminent collapse, go for it. If Aunt Sadie is about to breathe her last breath, be my guest.
Otherwise, hands off "Reply All".