1350
Literally, it's a shorthand reference to the FBI study which found that half (approximately 50%) of violent crime was perpetrated by a small minority making (13% of the population). Implicitly, it's a refutation of the claim you can conclude that law enforcement is systemically racist based on the fact that members of the minority group account for a disproportionate number of violent confrontations with the police.
She said, "how can you deny the cops are racist when so many more black men are shot," and he just said, "1350."
1350
A memetic phrase referencing the 2019 FBI crime statistic that roughly 50% of the violent crimes in the US was caused by a minority making up 13% of the population
Bro. stop quoting the 1350 ,the cause heavily disputed and we're here for 420
1350
Another stupid racist codeword racists use to identify each other, ala 1488. This falsely alleges that black people in America are 13% of the population and commit 50% of the crimes. Racists use codewords like this because they realise that their racism gets them ostracised from rational society unless they hide their stupidity.
"Hey Bobby, my screen name is '1350'! Aren't I funny? Anyway we still on to fuck our cousins later?"