As standard all Credentials are set to be publicly viewable. If you want to hide your credential from public view just follow these steps.
1) Head to your credentials unique URL. It looks something like this www.credential.net/123456789
2) Login - Click Login in the top left hand corner, send your self the validation code and then verify your identity to take ownership of the credential.
3) Once logged in, select 'Change Privacy Settings' from the left hand menu. Then change the settings from Public to Private. Your credential is now only viewable when you share the private key.