Back in the day CALEA was voluntary up to the point of a court order to
   customer. At that point we had to do some re-routing and install one of
   their devices at provider cost. This was early 90's -  IP Fabrics still
   carries it i think -

   [1]https://www.ipfabrics.com/products/deepsweep/index.html

   -------- Original Message --------

   Subject: Speculation as to why printer manufacturers have forensic
   tracking dots

   Local Time: November 18, 2017 2:58 PM

   UTC Time: November 18, 2017 10:58 PM

   From: ryacko@gmail.com

   To: cypherpunks@lists.cpunks.org

   [2]https://www.eff.org/pages/list-printers-which-do-or-do-not-display-t
   racking-dots

     (Added 2017) REMINDER: IT APPEARS LIKELY THAT ALL RECENT COMMERCIAL
     COLOR LASER PRINTERS PRINT SOME KIND OF FORENSIC TRACKING CODES, NOT
     NECESSARILY USING YELLOW DOTS. THIS IS TRUE WHETHER OR NOT THOSE
     CODES ARE VISIBLE TO THE EYE AND WHETHER OR NOT THE PRINTER MODELS
     ARE LISTED HERE. THIS ALSO INCLUDES THE PRINTERS THAT ARE LISTED
     HERE AS NOT PRODUCING YELLOW DOTS.


   I have a theory as to why. CALEA allows the government to compel "a
   manufacturer of telecommunications transmission or switching equipment"
   to modify the equipment. Under that or a similar law, printing
   manufacturers are compelled to put tracking information onto paper.

References

   1. https://www.ipfabrics.com/products/deepsweep/index.html
   2. https://www.eff.org/pages/list-printers-which-do-or-do-not-display-tracking-dots