In an interview with The Sun, a baggage handler revealed that when thieves see a suitcase with a padlock attached, it makes them believe there are valuables inside, making your suitcase a target.
Furthermore, padlocks on your suitcase really aren’t a deterrent for those who decide they want to break in, as all a thief needs to get inside your suitcase is a pen.
The zipper on a suitcase can be popped by pushing the pen tip through the zipper, and then the suitcase can be zipped back up simply by moving the padlocked zip heads along the teeth.
It may be better to purchase a suitcase with a lock built into the design, so thieves cannot cover up their attempts at breaking and entering. Another tip is to apply ‘Fragile’ stickers to your suitcase, as it may be treated with more care throughout its journey.