There is probably a very obvious answer to this question, but how exactly does Disneyland completely empty the park on the night of a Halloween Party, and how do they ensure that everyone in the park has a ticket for the party?
If you have a ticket for the party you get a wrist band. If you are caught without it you are asked to leave. If you try to get in line for rides, you won't be able to go on without the wrist band.
"You can cut me off from the civilized world. You can incarcerate me with two moronic cellmates. You can torture me with your thrice daily swill, but you cannot break the spirit of a Winchester. My voice shall be heard from this wilderness and I shall be delivered from this fetid and festering sewer."
People who attend the Party get wristbands, and there are people on Main Street and at the entrances to attractions checking that everyone who comes in after park closing has a wristband...it is surprisingly effective actually.