“Americans who turn to terrorism and plot against the U.S. are now as big a concern as international terrorists, Homeland Security Secretary Janet Napolitano said Sunday.

The government is just starting to confront this reality and does not have a good handle on how to prevent someone from becoming a violent extremist, she said.

In the last year, Napolitano said, she’s witnessed a movement from international extremism to domestic extremism – cases in which Americans radicalized and decided to plot attacks against the country. “

(Homeland chief: Domestic extremism is top concern – washingtonpost.com)