For Apple, iOS 5 is starting to become a minefield because every time a problem is solved, others appear in its place. The initial problems with the autonomy of the signal, etc., were not solved by Apple, but there are others besides them, and the most recent one has to do with sending text messages to groups of people. It seems that in iOS 5 there is a problem with sending a text message to a group of people, exactly those who receive the message sent to a group cannot only reply to the user who sent the message, they receive the phone numbers of the whole group and reply to the whole group when I send a text message.
I'm having the opposite problem — a friend sent out a group message. When I reply, the only thing I can do is to reply all — there's not the option to reply just to the person who sent the message. Now I have my friend's friends texting me "hi, who is this, I got a text from you." Is there a way to reply-to-only-sender? Also it seems like a bug that when you reply it's reply-all but there's no indication of that at the time you press Send.
The problem would not be so big if the Messages application would hide the numbers of the people who received a message sent to an entire group and if the same application would allow the person who received the message to reply only to the person who sent it and not to the entire group. Apple knows about the existence of this problem and it will probably be fixed in iOS 5.1, but in the meantime be careful how you send messages to groups of contacts because the phone numbers of the contacts will be displayed to all the people who receive the message.
