Disneyland has been informed that they are a potential terror target (well, duh.)
Here are their precautions to protect the thousands of people who visit daily:
Before you can enter the park, you must submit to having any bag you carry searched.
Metal detectors: Nope.
Clothing (coats bulky clothes, etc.) checked: Nope.
Fluids or other "suspicious items" checked: Nope.
So, if you were wearing a suicide vest, and decided to wait for a parade or fireworks show, you could quite easily kill 50 to 100 people. If you had any devices to plant (which could actually be harder because of the constant clean-up efforts) you could triple your body count. A few grenades tossed into the large crowds--with some flashbangs and tear gas added for effects: you could do much damage and get away clean. For even more effect, throw in a couple of submachine gun-carrying tangos shooting into the panic, or a few more explosive devices--tossed in trash cans at the major choke points, either timed or command detonated, and you could do damage to life on a scale comparable to 9/11.
Planning the logistics of such an attack is child's play. The tactics could be easily covered in a few days--from initial planning on google maps to a few recons by the players--who really would never have to meet prior to the day of execution, as long as they knew what to do and when. They could even use park-hopper passes to cover the park over a two-week period to guage days and time when they could get the most bang for the buck.
The effect on the national psyche would be huge. A large percentage of the killed and wounded would be children. There would also be a number of international tourists among the bodies. You want to strike fear? Kill randomly. If you want to achieve terror, strike at the heart of the population. Show that you will kill your enemy's children, that there is no safe place, that you will lay upon the altar that which they hold most dear.
And that is why I prefer to carry a weapon. If the grenades, random shooters, suicide vests, and IEDs don't kill me, I'd like to think that my dying breaths would be spent defending my family, instead of just cowering over them, hoping that the bullets and blasts don't find them, that my body is enough to shield them, that they won't be made to watch me perish while protecting them. I'd rather they see their father rushing to protect them, to do everything, giving his last full measure, to stop evil men from hurting the innocent.
In a microcosm, Disney serves as a great example of our own country. Borders so porous that all our security is really just a cursory bag check, controls lacking or non-existent to reduce the likelihood of attacks, and a general public blind to anything other than their own pursuit of happiness. As long as commerce (the ticket sales in this case) continues, and the economy continues marching, people will gladly sacrifice their security for liberty.
"Those who would sacrifice a little liberty for security deserve neither" is such a crock of shit. You have to sacrifice one way or another--you can't have both. I sacrifice the freedom of sleeping under the stars for the security of a locked house. I sacrifice the freedom of going barefoot for the security of not getting frostbite while walking in the snow. I sacrifice the liberty of carefree thought and behavior because I want to provide security for those around me.