[kalee]

I thought trailers were locked.

[Spktyr]

Some trailer ‘locks’ are just like those little crimp seals that close cable boxes on buildings.

[GOPJ]

"One involves thieves popping open the rear doors of a trailer and pulling out boxes of cargo – while the rig is sitting at a traffic light. True story. A trucking company that had been plagued with losses in the neighborhood video taped the incident, says a marketing executive at a security equipment manufacturer who saw the tape. What's pitiful about that incident, and others that aren't so well documented, is that the doors couldn't have been opened so easily had they been locked. Look at trucks and tractor-trailers going up and down the roads and parked at rest areas and truckstops, and you'll see plenty of unsecured cargo doors."

from link:

http://www.truckinginfo.com/article/story/2006/07/under-lock-and-key.aspx