>>723905773
Rap song containing the lyrics "67" referencing a police code "10-67 Investigate Report of Death." Preceding lyrics reference being a gang hitman with a Glock with an automatic fire modification on it.
The song became popular and Zoomers started using 67 as an essentially meaningless in-group shibboleth disconnected from its original song. There's been various attempts to explain it as being a reference to a 67th street in Chicago known for its high crime (the original rapper is from Philadelphia though) or a 6 foot 7 inches basketball player.