Block user
If user A blocks user B, then user A can still write a message to user B. User B does not receive the message. However, user A does not know this. It would be wise if user A could not send a message to user B. A message should appear: "You can't write user B".
Next problem: If user A blocks user B and he was previously a friend, user B will appear in the birthday list despite being blocked.
Next problem: User A blocks user B. Nevertheless user B appears in the list of suggested followers.
Since blocked users who were previously friends appear in the modules Birthday etc. and in the list of suggestions for followers, blocked users can be written to.
This is not a big problem, because user A wants to have silence from user B. But still it would be good if a notification appears that he blocked this user.
There was another problem with blocking users, but unfortunately I forgot this at the moment.