Kenwood anti-theft security: only for show?

After I replaced our car battery a few weeks ago, the stereo asked for the security code. Supposedly this makes it worthless to thieves because they won’t know the code. Cool.

Except, I don’t know the code either. I must have forgotten to write it down. Oops.

Kenwood’s website tells me the dealer can reset it but the 3rd Google result for “kenwood 519 security code” tells me how to reset it myself. So, it turns out the radio is only worthless to thieves who don’t know how to use Google. You can go look up the details yourself. It basically involves entering KCAR using the stereo’s remote. But don’t tell anyone: it’s a secret.