*Change your SSID to something unique. (No, "FBI Surveillance Van," while cute, is hardly unique.) Then make your network password something hard to guess. It's not rocket science.*
"OK got it...it's not rocket science.."
I seriously doubt this guy was within WiFi range and needed the SSIS. There is zero point making your SSID invisible or complex when there are tools like inSSIDer, NetStumbler, or Kismet that can scan the network for a short while to show all of the current networks out there. A hidden or complex SSIS does nothing to enhance your security. The biggest problem by far is not changing the default username or password on the camera.