From Vent, Enter, Search, a blog for firefighters about hazards and unusual situations encountered on the job. Much of what's documented is epic kludge that may also put firefighters in danger when trying to enter or exit a building.
It's possible this kludge was only made to keep the trunk from flapping. Sure. That's it. Because if it were meant to keep someone from opening it, it would only work for someone on the inside right? And that would mean... never mind, I don't want to think about it.