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