In Massachusetts, a young woman makes genetically modified E. coli in a closet she converted into a home lab. A part-time DJ in Berkeley, Calif., works in his attic to cultivate viruses extracted from sewage. In Seattle, a grad-school dropout wants to breed algae in a personal biology lab.

These hobbyists represent a growing strain of geekdom known as biohacking, in which do-it-yourselfers tinker with the building blocks of life in the comfort of their own homes. Some of them buy DNA online, then fiddle with it in hopes of curing diseases or finding new biofuels.

But are biohackers a threat to national security? […]

The man on the other end of the line was Nils Gilman, a researcher with Monitor 360, a San Francisco company that provides “geo-strategic” research. Mr. Gilman declined to identify his client, saying only that it’s a branch of the U.S. government involved in biosecurity. “I think they want to know, is this something we need to worry about?” he said — particularly, could the biohackers’ gadgets and methods, in the wrong hands, create dangerous pathogens?

Wall Street Journal: In Attics and Closets, ‘Biohackers’ Discover Their Inner Frankenstein