They don't get the contents of the message, and I don't believe (off the top of my head) that they get told who sent the message. It's just a "you received a m

They don't get the contents of the message, and I don't believe (off the top of my head) that they get told who sent the message. It's just a "you received a message" notification, that the phone then has to expand into the actual notification itself by talking direct to the server.