Vikings' Anthony Barr Gets Violent Hate Mail for Aaron Rodgers Injury

Packers fans are still pissed about Anthony Barr laying out Aaron Rodgers ... but one Cheesehead took it WAY too far in a disturbing hate letter for the Vikings star.

The violent threats were masked as a piece of fan mail -- wishing for Barr to get put in a wheelchair when the Vikes come to Lambeau Field next weekend.

"Proud of yourself? You're a piece of sh*t. You didn't have to throw him to the ground and purposely come down on top of him. Did you jump for joy when heard his (collarbone) crack?"

"SOB bastard. Come 12/23, hope you get your neck snapped. Remember Darryl Stingley? Your payback is coming. Piece of sh*t. Packers."

FYI, Stingley's an ex-NFLer who had his career (and life) cut short by a spinal cord injury.

Barr's tackle was kinda sketch, but with Rodgers ready to come back ... aggro, much??