Correcting Firefox DRM and letterboxing

private_dot_mozilla/private_firefox/private_personal-profile.default/user-overrides.js.tmpl

@@ -95,6 +95,15 @@ user_pref("browser.shell.shortcutFavicons", true);
 user_pref("network.http.referer.XOriginPolicy", 0);
 
 
+/*** [SECTION 2000]: PLUGINS / MEDIA / WEBRTC ***/
+/* 2022: disable all DRM content (EME: Encryption Media Extension)
+ * [SETUP-WEB] e.g. Netflix, Amazon Prime, Hulu, HBO, Disney+, Showtime, Starz, DirectTV
+ * [SETTING] General>DRM Content>Play DRM-controlled content
+ * [TEST] https://bitmovin.com/demos/drm
+ * [1] https://www.eff.org/deeplinks/2017/10/drms-dead-canary-how-we-just-lost-web-what-we-learned-it-and-what-we-need-do-next ***/
+user_pref("media.eme.enabled", true);
+
+
 /*** [SECTION 2800]: SHUTDOWN & SANITIZING ***/
 
 /** SANITIZE ON SHUTDOWN: IGNORES "ALLOW" SITE EXCEPTIONS ***/
@@ -129,3 +138,15 @@ user_pref("privacy.clearOnShutdown.cookies", false); // Cookies
 // user_pref("privacy.cpd.sessions", false); // [DEFAULT: true]
 // user_pref("privacy.cpd.cookies", false);
 
+
+/*** [SECTION 4500]: RFP (RESIST FINGERPRINTING)
+/* 4504: enable RFP letterboxing [FF67+]
+ * Dynamically resizes the inner window by applying margins in stepped ranges [2]
+ * If you use the dimension pref, then it will only apply those resolutions.
+ * The format is "width1xheight1, width2xheight2, ..." (e.g. "800x600, 1000x1000")
+ * [SETUP-WEB] This is independent of RFP (4501). If you're not using RFP, or you are but
+ * dislike the margins, then flip this pref, keeping in mind that it is effectively fingerprintable
+ * [WARNING] DO NOT USE: the dimension pref is only meant for testing
+ * [1] https://bugzilla.mozilla.org/1407366
+ * [2] https://hg.mozilla.org/mozilla-central/rev/6d2d7856e468#l2.32 ***/
+user_pref("privacy.resistFingerprinting.letterboxing", false); // [HIDDEN PREF]