Someone abusing full stops in text. Generally means the author is either a 13-year-old girl, pissed off, arrogant, or has a big fat ego.
Stewie: Hi dawg
Stewie: Wassup bro, yo fine?
Luke: Yes. Fine.
Stewie: u better be comin to my party this friday!
Luke: No. Don't think so.
Stewie: Shit bro, stop being like a 13 year ol fullstopper. Did u just wake up with a broom planted up yo ass?