Yahoo pulled the trigger and is suing Facebook over alleged patent violations. The digerati are outraged, and there might be more than a few engineers inside Yahoo that feel the same way. I’m no lawyer, and one can never predict what judges or juries will come up with, but some of those patents seem far-fetched. Who knew that Yahoo invented the concept of targeted advertising? Or instant messaging? It sure seems like there will be prior art on many of these. Facebook doesn’t have a big patent portfolio to negotiate with, and it may well choose to settle to avoid distracting its IPO. Yahoo sued Google before its IPO, and Google settled, but Yahoo’s Overture subsidiary really did invent paid search. Silicon Valley is hoping Facebook will fight, though I’m puzzled how Micrososft could help. Maybe it could buy Yahoo?