That is much easier at stadiums and enclosed venues, where security officials can check bags and scan spectators for dangerous devices.

BBC: Boston Marathon attack: How secure are marathons?

While the Transportation Security Administration may open bags to inspect them, wrappers at some U.S. airports, including New York's JFK and Miami's, are posted in secure areas to re-bind luggage that authorities have unsealed.

WSJ: To Meet the Biggest Wrap Stars, Stroll Through the Miami Airport

This year we did a similar thing and helped a non-profit come up with 750 bags of new security blankets, books and stuffed animals for homeless children.

FORBES: 'Traveling Red Dress' Movement Proves Social Media Foundation Is Still People, Empowerment