An aside, but one of my more fun small pranks involved two fortune cookies in the office circa 2007.

I extracted the real fortunes, and inserted two of my own. When a friend dropped by, I handed him one and took the other.

His fortune read "You are an asshat".

Which surprised him somewhat, differing as it did from the usual fare.

What blew him away was when I cracked my cookie and withdrew my fortune: "Your friend is an asshat".