This is a non-writing post today.
What ever happened to being nice to your coworkers? I don't care if you're stressed out or angry with someone else or overworked, it doesn't give you the right to say rude things to people.
That said, a lot of people don't think before they speak. Take a moment, take a breath. Say it in your mind and think "Will this crush someone's spirit if I say it to them? Would I be crushed if someone said this to me?" And then edit yourself accordingly.
And, if you're one of the people that continually says rude, uncalled for things to your co-workers, please don't EVER complain to me about receiving poor customer service. You probably deserve it--and worse!