Hijacking a Store's PA System

[Σnigma]

Not literally hijacking it, but just being able to broadcast onto a PA system at a Wal-Mart or grocery store. The store I work at doesn't seem to be a closed-circuit system because managers get portable phones that can accept calls and broadcast onto the PA system. So my question, how would one go about finding out what channel the PA system is on?

One idea is that I could use a walkie-talkie and scan frequencies outside of the grocery store until I hopefully pick something up.

Reason for hijacking it would be to terrorize the store for epic lulz.

[Steve]

I almost guarantee their radios work off a completely different band than walkie-talkies. You would need a radio scanner, and that's if their channel isn't secure.

[SLIM]

Ever wanted to get on the intercom of a supermarket and scare the shit out of everyone with a bomb scare? Now you can.

All you have to do is call up and ask to be transfered to a department. Once you're through tell them that you are from another department and that the page button is broken; they should transfer you to the intercom so that you can say whatever you want ;)

They probably have a new policy on this now and will require you to give a name of an employee or something like that to confirm you actually are an employee of that department.

Think of the possibilities with this; bomb scares for cash, you name it.

This worked about a year ago, shouldn't have changed that much.