If you block someone, they will not know. It's private and only you know. Here is how ooVoo behaves when using the Block or Remove features:
1. You Block Someone
When you block a user, you will still appear on their roster but always as being Offline. They will not know that you blocked them, but their attempts to make contact with you will not reach you.
2. Someone Blocks or Removes You
ooVoo will never alert you when you have been blocked or removed by a user. When you are blocked, the contact will always appear in your roster as being Offline.
3. You Remove Someone
The user is removed from your Friends list. However, if you do not block them prior to removing them, they will still be able to contact you.
If another user is harassing you or threatening your safety, please report them to the police, your parents, or your school.