Messages

I created a sublist of my contacts on the iCloud. I get the option to "Message All" when I press and hold the list title or name. The message dialoge opens populated with the list contacts. I can then type the message and send it. I do not want to expose the reciepients names the list members, only my name and number. I want any replys to to go only to me. This is like a blind copy when using email. I have groups turned off. I checked this and it worked for a while. Now it exposes the list of names to all reciepients. How do I fix this?