There's a good chance he could have also recovered a MAC from logs etc. What's more important is that you don't set your SSID to hidden: Someone needs to broad

There's a good chance he could have also recovered a MAC from logs etc. What's more important is that you don't set your SSID to hidden: Someone needs to broadcast the SSID for the connection to work, and if it isn't the AP, it will be your mobile device broadcasting it everywhere you go!