Where and how does others reading this verify this?

try downloading an encrypted pdf and opening it in Edge or Chrome and it will not print. Open it in Firefox and it does print. Basically Firefox is ignoring the encryption I've put on the pdf's I send out to attorneys.

I would suggest you open a bug to get input from Dev. https://bugzilla.mozilla.org/show_bug.cgi?id=792816#c12

Here are similar post...

https://support.mozilla.org/en-US/questions/1014746 https://support.mozilla.org/en-US/questions/1040127

Yes, the pdf.js JavaScript library defaults to allowing all usual actions such as copy and print. Mozilla doesn't deviate from the default when using the library in Firefox's built-in PDF viewer.

If you are showing users PDFs online and do not want them to print, one workaround is to embed them in a custom implementation of the pdf.js viewer on your website, rather than having them open in the browser's own viewer. Then you can control printing. See: https://github.com/mozilla/pdf.js/wiki/Setup-PDF.js-in-a-website

There seem to be a lot of sites that do that, judging from user complaints here that the download button was missing when they viewed a PDF.

Note - if anyone needs a secured document to test on: https://www.jeffersonscher.com/res/protected.pdf