It doesn't help that cops purposefully misuse those types of guns. If I recall correctly, they're supposed to "bounce" the round off the ground and into the target, reducing the total amount of force hitting the target since some of the impact will be reduced from the first impact on the ground.

The number of cops who just shoot people straight with these things point blank is too god damned high. However, you can still get deeply fucked up, even if they're using it "correctly."

Is that how you inspired your username?

I didn't say it wouldn't leave a bruise. Even solid armor plates won't stop that amount of kinetic energy without leaving a mark. But having soft padding between the projectile and your skin will reduce the abrasion and force of low-angle impacts. "Better than nothing" in this case means the difference between a deep bruise, and a deep bruise under potentially an open and bleeding wound.