Added important documentation about the debug module functions

howto/howto-debug-contacts-provider-tables.md

@@ -24,6 +24,27 @@ To log all of the above tables in a single call,
 Context.logContactsProviderTables()
 ```
 
+## This is not meant to be used in production code!
+
+DO NOT include usages of the `debug` module in your production code! It is only meant to be used
+as a debugging tool **during development**!
+
+There are several reasons why you should only use this for debugging.
+
+First, Contacts database tables may be very lengthy. Imagine trying to print thousands of contact 
+data! It would slow down your app significantly if you log in the UI thread.
+
+Second, Contacts database tables will most likely contain sensitive, private information about your
+users. If you are working on a contacts app and you are logging your user's Contacts database table 
+rows into remote tracking services for analytics or crash reporting, you could be violating 
+[GDPR](https://gdpr-info.eu) depending on how you use that information. Be careful. This is why
+logging functions in the `debug` module are not customizable and are not part of the core API.
+
+Other forms of logging outside of the `debug` module implemented by this library upholds privacy 
+laws. Private user data (user's contacts) are not logged at all.
+
+**The `debug` module is a power tool that should only be used for local debugging purposes!**
+
 ## Debug functions do not depend on the core library
 
 Notice that the `debug` module does not depend on the `core` module, or any other modules in this