diff --git a/docs/topics/telnetconsole.rst b/docs/topics/telnetconsole.rst
index 4db9cafb2..bf2ffa443 100644
--- a/docs/topics/telnetconsole.rst
+++ b/docs/topics/telnetconsole.rst
@@ -16,6 +16,17 @@ The telnet console is a :ref:`built-in Scrapy extension
 disable it if you want. For more information about the extension itself see
 :ref:`topics-extensions-ref-telnetconsole`.
 
+.. warning::
+    It is not secure to use telnet console via public networks, as telnet
+    doesn't provide any transport-layer security. Having username/password
+    authentication doesn't change that.
+
+    Intended usage is connecting to a running Scrapy spider locally
+    (spider process and telnet client are on the same machine)
+    or over a secure connection (VPN, SSH tunnel).
+    Please avoid using telnet console over insecure connections,
+    or disable it completely using :setting:`TELNETCONSOLE_ENABLED` option.
+
 .. highlight:: none
 
 How to access the telnet console
@@ -39,7 +50,12 @@ autogenerated Password can be seen on scrapy logs like the example bellow::
     2018-10-16 14:35:21 [scrapy.extensions.telnet] INFO: Telnet Password: 16f92501e8a59326
 
 Default Username and Password can be overriden by the settings 
-:setting:`TELNETCONSOLE_USERNAME` and :setting:`TELNETCONSOLE_PASSWORD`
+:setting:`TELNETCONSOLE_USERNAME` and :setting:`TELNETCONSOLE_PASSWORD`.
+
+.. warning::
+    Username and password provide only a limited protection, as telnet
+    is not using secure transport - by default traffic is not encrypted
+    even if username and password are set.
 
 You need the telnet program which comes installed by default in Windows, and
 most Linux distros.