There are a few signs that you have to look out for that may suggest that you have been blocked by someone: 1. In the chat window, you can no longer view a contact's last seen or online status. 2. No updates to a contact's profile photo are shown. 3. Any messages sent to a banned contact will always have one check mark (message sent) and will never have a second check mark (message delivered). 4. Any calls you try to make will be rejected. 5. If all of the aforementioned signs are present for a contact, it's possible that the individual is blocking you.