The term 420 comes from the Time in India with Brtish occupation. The term is generally considered racist and is defined as fradulently or maliciously stealing information or goods from someone with seeming control. More recently however the term can be related to social engineering and jacking shit like the archangle, "a killer, clean, cold blooded , thorough," whose alias is "Whitehats" and jacks shit like yellow jerseys, "no mercy"
"Have you seen my hat." " No, besides why would you need that dirty old thing happy 420, remain blessed"
420 has nothing to do with waldos whatsoever. 420 stands for April 20th, what is Adolf Hitlers birthday, which many people in the Netherlands(home to amsterdam) and Germany celebrated during Hitlers time by drinking alcohol and, smoking marijuana. The Tradition then made its way over to the United States through word of travelers.