OK, this thread is getting silly. I'm not saying the post above is silly (I quoted it for reasons I explain below), but I think we can all agree that there is a wide spread between an idiot/jerk bringing in a gun or knife to cause trouble and a coordinated attack by al Qaeda (which I'm pretty sure doesn't need to look to the Dis for ideas or tips). I don't know if Disney security is going to deter al Qaeda from attacking; I think we're going to have to rely on the CIA, FBI, U.S. Military, and many others to help us on that one. But will a bag check keep out, or deter, 99% of people? I think so. Some people feel they are window dressing, some people feel they make a difference. The challenge with this argument is that we'll never know what they prevented, if anything.
What I do know, and why I quoted the post above, is that a dedicated terrorist will always find a way. Believe it or not, crashing planes into buildings was a path of least resistance 10 years ago. Trucks and car trunks were thoroughly searched going into the WTC after al Qaeda's failed car bomb attack on the WTC in the early 1990s, so another approach had to be developed to take them down. And it wouldn't surprise me that they hate WDW with the same passion as they dd the WTC, because WDW represents America in many ways, and thus is a visible target. But if al Qaeda or another terrorist group decides to take on WDW, I think we're going to have to rely on the military, law enforcement and intelligence agencies to prevent that one.
So, in closing, I want to go on with my life and enjoy our time at WDW. That may be one of the things that can unite us all; as humans, we always rise again and move forward.