The FBI tracked down the CEO of MyPillow in an Arby's drive thru while he was enroute home from a hunting trip and showed a search warrant authorizing them to seize his cellphone. He was permitted to call his lawyer who told him to comply even though.....well, read the story.
Two lessons and thus the irony.
1. The FBI tracked him by his cell phone
2. You should always carry 2 cellphones in your car or at home. I mean, what else do you do with the old cell phone?