The dangerous 13-15 ounce mail

Stopping at my neighborhood Postal Service blue box to drop off a letter this morning, I was greeted by the "new 13-ounce rule." This rule supersedes the "16-ounce" rule, which required all stamped mail exceeding 16 ounces to be brought to an actual post office for delivery.

The change is part of ongoing security measures established by the Postal Service, in cooperation with other government agencies to keep the public, customers, employees and the U.S. Mail safe.

If anyone can find out, I'd love to know how prohibiting those extra 3 ounces in making America safer.