That would require a Firefox build without NPAPI support. A user can&#x27;t differentiate between Flash or Silverlight playing a DRM video and non-DRM video, so removing NPAPI support entirely would be the only sure method. Firefox users can disable Flash or Silverlight if they don&#x27;t want sites using plugin DRM. Likewise, Firefox users can remove the Adobe CDM or uncheck the &quot;Play DRM content&quot; setting if they don&#x27;t want sites using EME DRM.<p><a href="https:&#x2F;&#x2F;support.mozilla.org&#x2F;en-US&#x2F;kb&#x2F;enable-drm" rel="nofollow">https:&#x2F;&#x2F;support.mozilla.org&#x2F;en-US&#x2F;kb&#x2F;enable-drm</a>