Sign "O" the Times

The city of Oakland has 33 automated license plate readers at various locations throughout town, and Ars Technica got a hold of those records:

In response to a public records request, we obtained the entire LPR dataset of the Oakland Police Department (OPD), including more than 4.6 million reads of over 1.1 million unique plates between December 23, 2010 and May 31, 2014. The dataset is likely one of the largest ever publicly released in the United States—perhaps in the world.

After analyzing this data with a custom-built visualization tool, Ars can definitively demonstrate the data’s revelatory potential. Anyone in possession of enough data can often—but not always—make educated guesses about a target’s home or workplace, particularly when someone’s movements are consistent (as with a regular commute).

Chilling.

Would someone please explain to me what the hell all that data has to do with “to serve and to protect?”