The newer garage door openers have randomly generated digital codes that change every time just to prevent that. Not too long ago I watched a hacker on the youtube explain how easy it was to open pretty much any motion activated high security door. It can be done with a balloon or puff of smoke, if you don't have one of the keys that opens all of the keyed entry doors. Apparently they are all made by two companies so if you have the two keys you can open all of them. It's fun stuff. Security is always an illusion.