Cops are concerned about fake 911 calls ... that a copycat might use the emergency number to set up an ambush- Dallas shooting

There is predictable fallout from the Dallas massacre in police departments all over the country. We've spoken with a number of cops and brass at LAPD and surrounding agencies ... and here are some top of mind concerns:

-- Cops are concerned about fake 911 calls ... that a copycat might use the emergency number to set up an ambush.

-- We're told cops are talking about carrying extra weapons to ensure they're prepared for the worst. It's a
bigger issue now than ever before.

-- The brass is telling officers to always carry ballistic helmets, vests and other protective gear and have it instantly available.

-- There won't be 1-person patrol units for the foreseeable future.

-- Cops are being told not to advertise that they work in law enforcement while off duty.

That said, the brass is trying to reassure officers that not every call is an ambush and not to develop paranoia.