i dont know about now adays or every where else but back in the mid 80s i had my phone tapped. i got a call one day asking for me by my full name. when i said yes im here they asked if it was me they were talking to when i said yes they simply said thank you and hung up. they were getting a voice recognition.

also another way to tap is on wreless phones is between the base and the handset and to cature the signal as it is transmitted between the two.