There is a lot of trouble you can cause with a 6.5536 Mhz crystal. You may not be aware that many restaurants use radio to connect to the drive thru speaker. There is a bit of debate if the video is real. You certainly can modify a CB radio to jam the system at a drive thru. It would be a bit sloppy and illegal. If you accidentally jammed the nearby aeronautical band you'd get a visit from the man. But it is doable. However, I don't think you will find that rectifier in your toaster.