2005 Subaru Outback Security Alarm Triggers

The car just came out of Subaru Service to have the brake lines replaced.  
Now when I lock the car, the security light flashes fast and within 1 minute, the
alarm goes off, lights flashing and horn sounding.  Pressing any button on the
key fob, the vehicle remains locked and the security light flashes normally
(every 3 to 4 seconds).   I am not accidentally pressing the emergency button
and the alarm sound is different than what is generated with the emergency
button.  Any thoughts on what may be causing this problem and if it's
something that can be fixed without returning the car to the dealership?