A common and very dangerous misconception often seen on the Internet is the idea that a childhood immunization, the MMR vaccine, causes autism. This is completely false, but began when a man publistued a fasified and now discredited paper making that claim. He was later found to have received maney from lawyers representing parents of children with autism who wanted to sue the vaccine companies. Which criterion of critcal thinking is most cleady being violated by those who accepted the false claim?