So after YOU entered the room and YOU unpacked your belongings including your laptop and then YOU left the room, YOU want to complain that the hotel left the door unlocked?

Your hotel room is your home while you are there; you are responsible for your safety - the hotel is responsible for providing you with what you need to be safe (i.e.: locks on doors, in-room safes).

I think you need to learn how to be a more saavy traveller and take more responsibilty for your actions (or lack thereof).