Grammar Nazi's are by far the most hated people on the internet. Due to the simple fact you know in daily life their ether absolute nobody or somebody with nobody.
So they feel they have to adjust spelling and grammar because they genuinely believe that spelling, and grammar is the only way to live.
I would love to say grammar Nazi's are similar to Trolls (see Trolls), However this is not the case. They actually do get angry at unreasonable grammar, Even though they seem to forget that planet earth is multicultural and English is not some peoples first second or third language. However Grammar Nazi's only usually speak one language English.
Grammar Nazi's can only be found on the internet This is due to their absolute coward ness outside the world wide web. If a grammar Nazi was to exist outside the internet there head would presumably explode this is because in the real world, most humans speak somewhat slang, and if a random grammar Nazi was to correct someone on the high street for example, they would get the hardest punch on the face they could possibly receive.
I am the human version of a pokedex and this was about the human type Grammar Nazi
Boy1: hi boy2 how you today
Boy2: I am certain you mean. Hi Boy2 how is your day.