I'm certain you've seen this common abuse. If you haven't, a
glance through your spam folder will give you an opportunity to observe it.
An exclamation point is meant to be used with an interjection. If you're old enough to remember the Schoolhouse Rock video, an interjection "shows excitement or emotion. They're generally set apart from a sentence by an exclamation point, or by a comma when the feeling's not so strong." If you're not old enough to remember the video, click the play button.
You would not use a dozen commas or question marks in a sentence, and you should not use more than one exclamation point.
An author friend of mine teaches the proper use of exclamation points this way: They are to be used if your character is screaming, yelling, or hysterical. If your character is not screaming, yelling, or hysterical, they are not feeling the emotion strongly enough to warrant the use of an exclamation point. Even then, do not put them at the end of every sentence once you have established the character is screaming. If he's involved in a fight, and the reader knows he's screaming, show the emotion once or maybe twice with the exclamation point, and the rest of the time through body language.
Enjoy the video!
~Marie