One exclamation point will do! Using more than one is grammatically incorrect and stupid; it reduces the effectiveness of the symbol. Using more than one fosters an effectiveness-value system. 

If more than one exclamation point is used, the amount must be determined. How many should be used in a particular type sentence? Shall we make it a 1 through 10 system, or is ten, not enough? We could make it a 10 through 100 system--.  Oh yes, that's it, ten exclamation points would mean moderate exclaim, and up near one hundred would mean very much exclaim.

So, how many would really mean moderate exclaim, and how many would mean very much? You see, all this is subjective. So again, using more than one exclamation point is ridiculous. 

The same thing goes for the interrogation point (question mark).

Use logic!

Please pass this on--spread some logic.

Richard Stuart Otto, 7 Nov 2007