Federal investigators say Islamic State militants have begun using encryption devices as part of their communications to make it more difficult for authorities to follow leads.
NYPD Commissioner Bill Bratton says the department is more frequently coming across encrypted devices and that authorities are losing a lot of intelligence because of the issue.
Bratton says law enforcement agencies around the country are reaching out to companies that create applications for encryption, but he says they are not working with authorities to pursue any leads.
He also says thousands of well-armed security personnel are ready to protect the city in the event of a terrorist attack in New York City.
Bratton says intelligence is essential to protect against "soft" targets like restaurants and entertainment venues, which are especially vulnerable because they cannot be constantly protected.