yeah the uprotect.it guys are very facebook-centric and they let the user decide on privacy...

SecretSocial is a standalone service letting you engage users on SMS, Email or Twitter. So people you know and people you don't can be engaged...

plus we are conversation-centric... the topic and need to communicate dictates the initiation.... very different from group-driven messaging.

Try out the Chrome extension as well to experience it fully!