diff --git a/popup/popup.css b/popup/popup.css
index fa8524e..8c28f44 100644
--- a/popup/popup.css
+++ b/popup/popup.css
@@ -589,7 +589,7 @@ body {
     max-width: 280px;
 }
 
-/* ── YouTube Error ── */
+/* ── Unsupported extraction (YouTube, streaming, Bluesky, email UIs, etc.) ── */
 .youtube-error {
     display: flex;
     flex-direction: column;
diff --git a/popup/popup.js b/popup/popup.js
index 3be6fd8..d30332e 100644
--- a/popup/popup.js
+++ b/popup/popup.js
@@ -443,9 +443,12 @@ document.addEventListener("DOMContentLoaded", async () => {
     return;
   }
 
-  // Check if this is a YouTube video
-  if (isYoutubeUrl(currentTabUrl)) {
-    showYoutubeError();
+  const unsupportedExtraction = getUnsupportedExtractionInfo(currentTabUrl);
+  if (unsupportedExtraction) {
+    showUnsupportedExtractionError(
+      unsupportedExtraction.title,
+      unsupportedExtraction.message,
+    );
     return;
   }
 
@@ -1531,18 +1534,77 @@ function isPdfUrl(url) {
   return pathname.endsWith(".pdf") || pathname.includes(".pdf?");
 }
 
-function isYoutubeUrl(url) {
-  if (!url) return false;
-  // Check for YouTube video URLs (youtube.com/watch or youtu.be/short)
-  const urlObj = new URL(url);
-  const hostname = urlObj.hostname.toLowerCase();
-  const pathname = urlObj.pathname.toLowerCase();
-  // Match youtube.com/watch?v= or youtu.be/VIDEO_ID
-  return (
-    ((hostname === "www.youtube.com" || hostname === "youtube.com") &&
-      pathname === "/watch") ||
-    hostname === "youtu.be"
-  );
+function unsupportedHostSuffixMatches(hostname, suffix) {
+  const s = String(suffix).toLowerCase();
+  const h = hostname.toLowerCase();
+  return h === s || h.endsWith("." + s);
+}
+
+function unsupportedUrlRuleMatches(hostname, pathname, anyOf) {
+  if (!anyOf || !anyOf.length) return false;
+  for (const part of anyOf) {
+    if (part.hostEquals) {
+      if (hostname === String(part.hostEquals).toLowerCase()) {
+        return true;
+      }
+      continue;
+    }
+    if (part.hostIn) {
+      const hosts = part.hostIn.map((x) => String(x).toLowerCase());
+      if (!hosts.includes(hostname)) continue;
+      if (part.pathnameEquals !== undefined) {
+        if (pathname === String(part.pathnameEquals).toLowerCase()) {
+          return true;
+        }
+        continue;
+      }
+      return true;
+    }
+  }
+  return false;
+}
+
+/**
+ * Sites where page text isn't extractable like a normal article (streaming, apps, banking, etc.).
+ * Rules live in `CONFIG.UNSUPPORTED_EXTRACTION.RULES` (`scripts/config.js`).
+ */
+function getUnsupportedExtractionInfo(url) {
+  const rules =
+    typeof CONFIG !== "undefined" && CONFIG.UNSUPPORTED_EXTRACTION?.RULES;
+  if (!url || !rules?.length) return null;
+
+  let hostname;
+  let pathname = "";
+  try {
+    const u = new URL(url);
+    hostname = u.hostname.toLowerCase();
+    pathname = u.pathname.toLowerCase();
+  } catch {
+    return null;
+  }
+
+  for (const rule of rules) {
+    if (rule.kind === "url") {
+      if (unsupportedUrlRuleMatches(hostname, pathname, rule.anyOf)) {
+        return { title: rule.title, message: rule.message };
+      }
+    } else if (rule.kind === "host") {
+      if (unsupportedHostSuffixMatches(hostname, rule.hostSuffix)) {
+        return { title: rule.title, message: rule.message };
+      }
+    } else if (rule.kind === "labeled") {
+      for (const [suffix, label] of rule.sites) {
+        if (unsupportedHostSuffixMatches(hostname, suffix)) {
+          return {
+            title: `${label} isn't supported`,
+            message: rule.message,
+          };
+        }
+      }
+    }
+  }
+
+  return null;
 }
 
 function showPdfError() {
@@ -1564,8 +1626,7 @@ function showPdfError() {
   `;
 }
 
-function showYoutubeError() {
-  // Hide initial state and show error
+function showUnsupportedExtractionError(title, message) {
   initialState.classList.add("hidden");
   resultContainer.classList.remove("hidden");
   footer.classList.add("hidden");
@@ -1574,10 +1635,8 @@ function showYoutubeError() {
   resultContainer.innerHTML = `
     <div class="youtube-error">
       <div class="youtube-error-icon">:(</div>
-      <div class="youtube-error-title">YouTube videos aren't supported</div>
-      <div class="youtube-error-message">
-        This extension can't extract text from YouTube videos at the moment.
-      </div>
+      <div class="youtube-error-title">${escapeHtml(title)}</div>
+      <div class="youtube-error-message">${escapeHtml(message)}</div>
     </div>
   `;
 }