The server means may comprise a controlling server and a participating server, wherein {HEAD ~ the controlling server} is arranged to receive the anonymity request from the first user, and the participating server is arranged to transmit {TAIL ~ the user plane message} 
The server means may comprise a controlling server and a participating server , wherein { HEAD ~ the controlling server } is arranged to receive the anonymity request from the first user , and the participating server is arranged to transmit { TAIL ~ the user plane message }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL