It's not just car break-ins. I drive a truck and it was about 2 yrs ago I started hearing about truck tailgates being stolen here in my area. The thieves will easily lift up most tailgates from the bed and then scrap the steel for cash. In these times scrap metals are paying well (another reason to save your brass.) Someone down the street had theirs taken from an F150.
I decided to buy a simple locking device. A Master Lock tailgate lock is less than $15. A tailgate can cost you close to $500 to replace.
Amazon.com: Master Lock 8253DAT Tailgate Lock: Automotive@@AMEPARAM@@http://ecx.images-amazon.com/images/I/41DpUzKyzsL.@@AMEPARAM@@41DpUzKyzsL
Just throwing it out there for those of you with trucks.