Anything's possible at any point. A crazed gunman could shoot up a mall or restaurant you visit. A group of terrorists could hijack one of the thousands of commercial liners that fly every day in the US and pilot it into another skyscraper. The London subway bombing, the Boston marathon bombing, all of these events could easily be duplicated...but we don't change the way we go about our daily lives, and we don't give in to fear and hysteria, right? That's all I'm saying.
I'm not saying we do change the way we go about our lives, I was merely pointing out that the plane could be used as a weapon as they've been used as weapons in the past, something you said you couldn't see how it could be used as a weapon. To write that off immediately and just assume this was an accident/crash seems goofy to me given all the "evidence" that's come out so far. Maybe it did crash, I kinda hope so, the only reason I don't is because of those folks on board, but I do because I don't want this thing to show back up years down the road and fly into a stadium packed full of people at 600mph. People have a false sense of security at all times, unfortunately that's not the world we live in anymore. It all changed after 9/11 IMO..............scary/sad stuff.