Five-seveN semi-automatic pistol
someone critiqued a movie, and gave it a 5/7, but then went on to say it got a full score from him.
Someone said something to him about it, like "5/7 isn't a full score, blah blah" and the 5/7 guy got mad.
So now everyone has just been making fun of it.
Like, the guy said "I'll do something about this in 5 days" (or whatever), and the people making fun of him said something like "See you in a week, then"
TL;DR its dumb.