They are masters at the "big lie". Repeat a lie enough times and people start believing it. The Jenin massacre story is a perfect example. The Palestinians kept repeating the big lie that hundreds of civilians had been massacred (in fact, they are still repeating it, after it has become perfectly clear to even groups like Human Rights Watch, who is no great friend of Israel, that there was no massacre) and the rest of the world bought it. Another great example, is the Sept. 11 story. A large part of the Arab world believes that Israel was somehow responsible, and believes that Jews received word not to go to work that day. In the West, that story is looked like as a joke, but in the Arab world it is taken very seriously.