UNObomber

You're the best Special Detective in the whole FBI, the guy they fly in when national security, the continued existence of the planet, the very fabric of reality itself is in jeopardy. But this time, you're not sure that you can do it. At first, it seemed like a harmless prank: At family evenings all over the country, suspicious UNO decks turned up, some with missing, some with extra cards. Gradually, the tampering became more extreme, as strange cards of unknown manufacture appeared: "+3", "-1/2", "Double Reverse", and similar nonsense that pointed towards a deranged, but brilliant - and ruthless - mind. When the papers stopped paying attention to the inter-generational brawls erupting over allegations of cheating at UNO, this madman upped the ante: Official tournaments were disrupted by counterfeit decks with mirrored cards, differing colors, and corrupted manuals. Finally, when the Dallas Open turned into a massacre during the now-infamous "+4 incident", the newly named "UNObomber" made the FBI's Most Wanted, and you were called in to crack the case. So far, your investigations have led nowhere - the UNObomber expertly hides his tracks, varies his MO, and increases the complexity of his game faster than you can analyze the clues. The DOJ is yards up your ass, and you're just about to throw in the towel and retire early. Suddenly, an out-of-breath assistant bursts in, hefting a huge stack of Xerox pages...