When "lets spend the resources to track this suspect" becomes "lets look at the universal tracking logs to see if we can drum up some criminals to suspect" because technology made tracking free, you have a problem.
Drug dogs. Let's deal with that problem first, OK? Because we appear to have outsourced the 4th Amendment to dogs. I have a dog. My dog's jurisprudential capabilities are highly suspect.
http://www.supremecourt.gov/oral_arguments/argument_transcri...