The phrasing comes from the standard safety disclaimers used on stunt and daredevil television, where announcers warned viewers not to imitate dangerous acts at home because death or injury could result. Clips of that warning were lifted and reused online as a standalone meme sound, detached from any specific show. Editors now drop it in as a mock legal disclaimer before fails, pranks and homemade stunts. Its popularity endures because audiences recognise the formula instantly, even without knowing the original broadcast it was copied from.