Postal service regulations govern thousands of items shipped daily, but few agencies have had to account for the aerodynamic properties of kinetic combat techniques. A retired mail carrier named Patricia Greenwood claimed in 2003 that her postal facility received unusual training protocols following an employee encounter. The USPS, she explained, had to clarify in internal memos that packages containing no prohibited devices yet arriving with subjects experiencing sudden head trauma would still be classified as mail tampering rather than product defect. Her testimony appeared in a quirky industry newsletter about unusual liability claims.

The mental image of envelope-delivered violence has lodged itself in internet folklore as the perfect fusion of mundane postal service bureaucracy and action movie physics. Social media threads regularly joke about the USPS needing to add a new hazmat category for armament delivery, complete with signature confirmation and insurance waivers. Memes featuring postal service warning labels overlaid with martial arts imagery have circulated for years as commentary on over-the-top security theater.