1. Login to Liferay server
2. Add one asset publisher and article
3. Enable comments in Aseet Publisher configuration
4. Now Logout from the portal
5. Add comment as a guest using "X" email id.
6. You will see a message to created acount in portal after commenting, click Cancel.
7. Now login through facebook account from login portlet. When you will login through the same "X" email id, which you used for guest commenting.
Result: An inactive user will be created
As opposed to: When creating an account the traditional way, Liferay will allow you to "connect" the two account or create a new one. This functionality should also happen when connecting through facebook.