<p><pre><code>  It quoted a Kansas man with experience in public-safety 
  technology as saying the van contained gear including &quot;infrared 
  cameras to find plate numbers and letters via temperature 
  differentials between those characters and the surrounding 
  background through optical character recognition.&quot;
</code></pre>
This guy is confusing near infrared (0.75 µm) with thermal infrared. (8–15 µm)<p>Near infrared cameras are cheap. Thermal infrared cameras are expensive (exotic materials needed for the optics) and have poor resolution, which makes them a really poor choice for machine vision stuff. License plate cameras are near infrared.