The interrobang is almost a real thing, and Dan Brown is successful enough to demand that his publisher give him a font that includes one, like so:

His breathless, italics-laden style is what the interrobang was designed for.  Here are some random examples from Inferno:

What the hell do they think I did? Why is my own government hunting me?!

Here he needs interrobangs in consecutive sentences:

Has the speech been canceled?! The city is in near shutdown due to the weather . . . has it kept Zobrist from coming tonight?!

This example is in Italian, although the translation apparently doesn’t require one:

“Lei è Robert Langdon, vero?!” You’re Robert Langdon, aren’t you?”

Here Brown reverses the order of the punctuation marks, for some reason that is too subtle for me to make out.  Perhaps we need a banginterro for this usage:

He turned to the woman. “How do we get up there!?”

Somewhere I learned the rule that a writer should avoid exclamation points: your prose should convey the excitement, not your punctuation. But Dan Brown doesn’t need such lessons; he needs the interrobang.

By the way, let’s not confuse the punctuation mark with this local band that I’ve actually heard play (and some of whose members have hung out at my house).  Or this other band with almost the same name.  With so many great names for bands floating around the universe, why is this happening?