The Los Angeles Times reports: Islamic State militants and their followers have discovered an unnerving new communications and recruiting tool that has stymied U.S. counter-terrorism agencies: instant messaging apps on smartphones that encrypt the texts or destroy them almost immediately.

In many cases, U.S. intelligence and law enforcement agencies can’t read the messages in real time, or even later with a court order, because the phone companies and the app developers say they can’t unlock the coded text and don’t retain a record of the exchanges.

“We’re past going dark in certain instances,” said Michael B. Steinbach, the FBI’s top counter-terrorism official. “We are dark.”

The hole in U.S. surveillance capabilities was not mentioned during the recent congressional battle over the National Security Agency’s bulk collection of U.S. landline and cellphone data. Lawmakers ultimately agreed to scale back that program because of concerns it violated Americans’ privacy.

FBI officials now want Congress to expand their authority to tap into messaging apps such as WhatsApp and Kik, as well as data-destroying apps such as Wickr and Surespot, that hundreds of millions of people — and apparently some militants — have embraced precisely because they guarantee security and anonymity. [Continue reading…]