Haven't used this pacsafe yet, but will be on an upcoming overseas trip.  I have no doubts that this will be an excellent backpack for my purposes.  I have a pacsafe pocketbook I've been using for 6 years - love it!!  This backpack will make a great carry-on and hopefully keep out the pickpockets.  We've had things taken (camera, etc.) out of our carry-ons using just a regular backpack while sleeping.  We didn't think we would need locks on it - HA!  So, we've learned a lesson and purchased these pacsafe backpacks.  Still thinking of putting locks on it, too!  p.s.  You'd think you could trust people on a plane!