Using the firefox-esr package currently in stable, visiting any page with EME media causes a "you must enable DRM" nag bar to be displayed with an "enable DRM" button. A single click enables DRM and causes the proprietary wildvine plugin to be downloaded, installed, and executed. There is no setting that disables this nag box or prevents it from installing the plugin.
Example page: https://bitmovin.com/demos/drm There's no way this behavior is appropriate for a package in "main".
