I am pretty sure it might have gone from cs/hltv. A lot of cs players had 1s in their nicknames, like s1mple or dev1ce, b1t, sh1ro. So every time they played poorly haters would rename them into s0mple, dev0ce, b0t. Then the folklore slowly developed and went personally into every player. ZyPoo, Defecto (instead of perfecto), ChoKo, midnesy, div0rce (device got cheated on, so it was really unfair).