Now Playing: 6-13-13 Marketplace Tech: Hurricane hack jam

New York City Mayor Michael Bloomberg has laid out a $20 billion plan for fortifying his city from future giant storms like Sandy. The plan includes everything from installing storm surge barriers to setting resiliency requirements for telecom providers. Whether and when these 250 recommendations will be implemented remains to be seen. But some of the city's tech-minded residents aren't waiting around. And, behold, the Facebook hashtag is upon us.