I was surfing the web and came across this news report. it says that third row seats in SUVs are being stolen and sold, especially in Texas and California. When I had my pickup I always had possible tailgate theft in the back of my mind, so I put a lock on it. It looks like in the video the tahoe was unlocked, so the guys just opened it and took the seat.

http://autos.aol.com/article/suv-minivan-seat-theft/