> Setting the PID to 0x64 would be a silent SMS known as a 'type 0' SMS which all handsets receive and must acknowledge without indicating its receipt to the user. As previously mentioned, this has been used by law enforcement to actively 'ping' a handset on a network.

I don't like that. Why should a device that I have paid for contain this backdoor? Manufacturers should not forget from whom they get the money.

It might be difficult to fix in hardware but if it is handled in software then open source projects like Android could do it and do not reply to silent SMS or display them to the user.