Colin Kaepernick: Cops Threaten To Pull Officers From 49ers Games

Colin Kaepernick's protest against police brutality has Santa Clara cops pissed ... in fact, they're so pissed, some are threatening to stop working 49ers' games.

In a letter sent by The Santa Clara Police Officer's Association, members call the QB's statements about cops, "insulting, inaccurate and completely unsupported by any facts."

The letter continues, "If the 49ers organization fails to take action to stop this type of inappropriate workplace behavior, it could result in police officers choosing not to work at your facilities."

As TMZ Sports reported ... Kaepernick has received both heat and praise from across the country for choosing to sit in silent protest during the national anthem.