The idea of "strikes" is pretty standard in the US from the 90s era "3 strikes" crime laws (i.e. commit 3 crimes and you get life without parole; these have gen

The idea of "strikes" is pretty standard in the US from the 90s era "3 strikes" crime laws (i.e. commit 3 crimes and you get life without parole; these have generally been repealed in the last 5-10 years or so) that were inspired by the rules of baseball where the batter is out after 3 unsuccessful swings or hittable pitches he didn't swing at. It isn't a good system but Youtube in particular was loaded with pirated content in the early days before Google invented automated copyright moderation so they most likely needed to do something drastic to delete pirate accounts to avoid legal trouble with the copyright lobby and everybody else just copied the idea as a "best practice".