He said it would even protect them from bullets fired by the white men's guns.

VOA: special.2010.04.08

Even as bullets impacted all around him, Sal grabbed his friend by the vest and dragged him to cover.

WHITEHOUSE: Medal of Honor for Staff Sergeant Salvatore Giunta

Secrets have become much more difficult to keep in the age of social media, even if bullets remain just as deadly.

FORBES: The Mutual Knowledge Revolution

The study also highlighted previous research which suggested that even plastic bullets may not be safe and may cause more severe head injuries.

BBC: Doctors urge rubber bullet ban