Yes, Mike is right – that style is usually called “ASCII art”.
There are several ascii art plugins for after effects, that actually could help you to create stylized videos –
“ASCII Generator”, which makes ascii-logos like in old h4x0r “nfo” files – what’s cool about it is that it actually makes text tables so you can animate it with AE’s text animation tools;
also there’s “L3tt3rm4pp3r” (what a name) – that plugin lets you to convert your video frames to frames made of symbols (ie you can use some old PC font or draw your own) and it is really fast – way faster than usual AE scripts.
Hope that helps, but basically it is what you will pick up from googling for “ascii art ae plugins” anyway.