If this sounds mean and certain people who do this feel offended, too bad. Get over it. It's not personal.
People: you've got to stop using 'reply all'.
First of all, we don't care what you have to say, we really don't. Usually, people email to a group out of convenience rather than emailing individually. But what is the 'reply all' offender's reason? It's not laziness or convenience, cause it's the same amount of effort to press reply and reply-all, buttons which are usually next to each other. If the email could be equally expressed by sending to an individual, then the reply should be to the original sender(s) only. If you think there is someone else on the group of recipients who might be interested in seeing your response, then add them separately to your address line as well. But otherwise, just press reply.
On a related note, you can't use the excuse that you pressed the wrong button by accident. If you're that stupid, you shouldn't be emailing...you probably can't compose a decent or even comprehensible message to begin with worth reading. So don't bother.
Secondly, it's just plain rude...to not care that people are being copied in unnecessarily. It's just inconsiderate of my time and resources. Do people who reply-all really think that their response is so wise and important that we all have to hear about it? Do I not have better things to do with my time than to read your two-cents and have to delete each of your useless emails to avoid clogging up my inbox? What if people's inboxes are at work? What if the inbox is limited in space or near capacity? Of course, there are exceptions but I find it's very rare where the exceptions do apply. Hence, they are exceptions because if they were more common, it would be the majority. Just rudeness. That's all it is.
But to be fair, there has to be some responsibility on the part of the sender. There has to be a sense of responsibility when sending and using email in general. For allowing people to reply all in the first place, you're just inviting trouble. Especially if you know people on your list of recipients a) aren't especially considerate, are selfish or usually immature b) lack email etiquette or life etiquette c) are just insecure losers who crave attention by having others see their worthless opinions/comments. Just don't give them the opportunity. Email responsibly. You wouldn't have sex or drive recklessly (most people at least), so why would you openly email to a group of people? Here's a trick....just like condoms and seatbelts, try B.C.C. In case you don't know what that means, it's an acronym for "blind carbon copy". Not an overly technical or complicated term but I'll explain it to you anyway, just in case. It means recipients in this address field cannot be seen. AH HA! A perfect and easy solution to tempting people with reply-all syndrome. And an extra bonus, the bcc field is located just two lines below the "To:" address field, so actually closer to the message text and therefore more convenient with less mouse movement required. Also, bcc also aids in the fight against spam as it reduces email addresses stored in your cache or address book. If they cannot see who is on the recipient list, hence they cannot reply-all. Wow, what will they think of next.
So, in summary:
1) Do not reply-all recklessly.
2) Use bcc when sending to a group.
3) The above rules are not absolute but when in doubt, just follow them.