Ah well, there you go... So you should always take into consideration that other users are having group messages ON on their phone. meaning that they can always see who else receive the message. I do receive some group messages from time to time, but i've never come to see other receivers contacts, also when i reply, my belief is that i'm replying to only the sender since i can only see only the sender contact in the recipient field. And that group message setting is ON on my iPhone. It's interesting to see that maybe my phone is having a bug or a feature? I can't tell.