Even though bolt cutters can make short work of the cable lock, those do serve a decent purpose, and that is to waste a would-be thief's time. Instead of grabbing stuff out of the bed, he has to jump in with tools and start cutting, which makes him noticeable.

 

Thought I'd throw this out there for anyone interested in putting in the cable lock:

I negotiated the deal on my truck to include the dealer throwing in the factory drop-in liner, bed extender and cable lock.
When I went back to have the accessories installed, it turned out that the three would not work together w/o modification.

The drop-in bed liner prevented the cable lock from lining up with its mounting holes so I made the dealer have a spray-in done instead.
I couldn't bear the idea of having the idiot who tried to install them in the first place touch my truck again, so I accepted the cable lock uninstalled.

Once the liner was done, I installed the cable lock and found that the bed extender half would scrape on the housing, so I bored out a couple washers to use as a bushing to add 1/8" extra clearanxce between the extender and the bed- all's well now.

Also of note, I wasn't happy with the two small tie-down bolts holding the cable lock in so I modified the mounting plate so it would sit far enough rearward to let the housing touch the pillar at the rear of the bed. Then I removed the tail light and drilled through the pillar and bolted it on there as well.
The F150 and F250 use different sides of the housing to bolt to, so I used them both - feels much more rigid now.

 

I learned firsthand about drop-in bedliners affecting lock placement. I bought a Master lock (http://www.masterlock.com/product_de...curity/8287DAT) to see how well it worked, eventually intending to buy four for each mounting.

Try as I might, it would not mount with the drop-in bedliner.