90951 

Someone so old school Riverside, California that they have lived through both area codes, 909 and 951.
Also a reference to a new school "bro". A reference to basically every guy in Riverside, as distinguished by wearing sleeveless black jerseys, black skater hats, black shorts, lifted trucks with a grenade sticker on it.

That Bro is so "90951", he just got another grenade tattoo on his hand.

90951 by MC Thermos April 14, 2009

90051338 

YOU GOT THE CODE AND THE MONEY I GOT YOU THE PS4
GG EZ

PLEASE ACCEPT I NEED MONEY 90051338

90051338 by ALEX THE CREEPY GUY WATCHING U January 16, 2019

90051338 

YOUR FUCKING UGLY FAT AND NEED TO KYS

ACCEPT IT SO I CAN SEND THIS D}TO PEOPLE

90051338

90051338 by ALEX THE CREEPY GUY WATCHING U January 24, 2019

Christian.9091 

Cuck

Oh you let your wife bang other dudes while you watch and jerk off? That's Christian.9091 shit right there

Christian.9091 by FUCKFACEMCGRIDDLE September 4, 2019