HTTP 403 forbidden error, when posting to a user wall via facebook graph api for a particular user

I am getting HTTP 403 forbidden error, when posting to a user wall via facebook graph api for a particular user. This error does not come for other users. Even if I reconnect this user to facebook ie get the access token again, the same error persists. He has the permission to post on the wall.

Our application had the ability to publish on the wall of all his friends. This particular user had tried to publish on the wall of all (500+) users.

Is there a possibility that facebook ha开发者_如何学Cs banned this user.

If yes then what is the way to unblock this user.