Happy slapping began in South London , particularly the London Borough of Lewisham , The first use was as Slap Happy TV , where many people would watch and judge the exploit of a happy slapper . Happy Slapping is known to have started in the South London London Borough of Lewisham , in a format known as `` Slap Happy TV '' , where a happy-slapping video would be recorded , and then watched by dozens of people like a TV show .