Schneier on Security

The Baltimore housing department has a new tool to find homeowners who have been building rooftop decks without a permit: aerial mapping. Baltimore bought aerial photographs of the entire city and used software to correlate the images with databases of address information and permit records. Inspectors have just begun knocking on doors of residents who built decks without permission.

On the face of it, this is nothing new. Police always have been able to inspect buildings for permit violations. The difference is they would do it manually, and that limited its use. It simply wasn’t feasible for the police to automatically document every building code violation in any city. What’s different isn’t the police tactic but the efficiency of the process…