I have posted this before but do so again for the new comers. Opening a passengers luggage is very simple, only a very few security systems will beat the determined thief.
A strong canvas or similar strap around the case with a very simple fastening of buckles will do, anything that is plastic and involves 'clicking in' is useless.
Many cases like Samsonite and Delsi have a single hinge down the back. A specially fashioned motor cycle spoke is all that is needed!
The thief applies the spoke, punches out the hinge, opens the case from behind and feels around for anything that feels expensive and saleable, case then closed, hinge replaced and case arrives at the carousel looking in mint condition, you only discover your loss when you get home.
ANYTHING that will cause time is to be considered, including plastic wrapping, if the thieves can't open your case and rifle it in seconds they can't take the risk. My favourite, a sturdy canvas strap that has a very simple metal buckle that can be pulled very tight on a very well travelled Samsonite.
If you choose to travel with soft canvas bags that can be ripped open with a knife, or the zippers can be opened with a Biro then you are asking for trouble. Genuine LV luggage is for stashing in the back of a racing green Bentley and never letting out of your sight!