Funny, I'm reading the defining book on tank warfare right now; Achtung! Panzer- about the effective use of tanks. Written in 1937, it draws from WWI experience on both sides. A battle between tank designers, anti-tank weapons designers and military leaders. The early English and French tanks were unstoppable except by shell holes, breakdowns, etc. The Germans invented armor piercing bullets. Better armor plating appeared. The Germans started mounting their cannons on carriages that shot horizontally at close range instead of the high arching lobs that worked so well against infantry. (It's early 1918. I don't get to see what's next until I pick the book up again tonight.)

Replace tanks with bike locks. The allies with us cyclists and the Germans with thieves and you have this thread. (Not really fair to the Germans. WW1 wasn't about right and wrong. Historically, we (the Allies) became "right" because we won. And rubbed it in so hard we paved the way for Hitler.) And just like tanks, bike locks keep getting bigger and more expensive. (Shall we place bets on when the fanciest lock's weight crosses that of the early tanks? )