diff --git a/docs/howto/error-reporting.txt b/docs/howto/error-reporting.txt
index afa6da0ff6..da7d487cdc 100644
--- a/docs/howto/error-reporting.txt
+++ b/docs/howto/error-reporting.txt
@@ -114,6 +114,14 @@ and override its methods.
 Filtering error reports
 -----------------------
 
+.. warning::
+
+    Filtering sensitive data is a hard problem, and it's nearly impossible to
+    guarantee that sensitive won't leak into an error report. Therefore, error
+    reports should only be available to trusted team members and you should
+    avoid transmitting error reports unencrypted over the Internet (such as
+    through email).
+
 Filtering sensitive information
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~