I say yes on bag check. But.... like someone posted it's just as easy for someone to have a small knife or something in their pants or shoe or where ever. Just like the other topic Big Brother is watching us all the time.
I always carry a pocket knife with me and Disney never blinks an eye. Of course I got wanded at the Sugar Bowl this year and my knife didn't set the wand off.
My biggest problem with the bag checks is how it makes a bottle neck. So this is what I would like to see a bag check set up at EPCOT over near where the Disney buses are to lessen the lines by the trams. I always try and use the side bag area coming from the parking lot at Hollywood. I like how AK's line is far enough out there so there really is no congestion. At MK I usually try going to the far ones to the right unless a fairy-boat is arriving at the same time.
Of course in a perfect world I wouldn't have to take a bag, but the wife 99% of the time thinks we should be over prepared.
In general bag checks make me feel safer. However, on our last trip at DHS I had a small backpack and I had stuff like sunglasses, wallet, sunscreen, etc. all at the bottom of my bag and then I packed my sweatshirt on top. The Security guy had me open my bag, saw the sweatshirt, then walk on in. No taking it out, nothing. Granted a look like a 12 year old high on disney magic when I enter the park, I still was surprised he didn't check more. Coincidence that this was the same day as the gun incident at Animal Kingdom.
I would place bets on that they're there for peace of mind. Six Flags New England is a little much for a theme park, I mean it definitely made me feel safer but still. I feel like Disney draws a different crowd than Six Flags. I feel safer in general at Disney than I do anywhere else, regardless of bag checks.