-        if '>Reset your password<' in response:
-            self.report_warning('Twitch asks you to reset your password, go to https://secure.twitch.tv/reset/submit')
+        try:
+            response = self._download_json(
+                post_url, None, 'Logging in as %s' % username,
+                data=urlencode_postdata(login_form),
+                headers=headers)
+        except ExtractorError as e:
+            if isinstance(e.cause, compat_HTTPError) and e.cause.code == 400:
+                response = self._parse_json(
+                    e.cause.read().decode('utf-8'), None)
+                fail(response['message'])
+            raise
+
+        if response.get('redirect'):
+            self._download_webpage(
+                response['redirect'], None, 'Downloading login redirect page',
+                headers=headers)