What is "phone hacking"

n. the act of intercepting and listen in on telephone calls or voicemail messages without the consent of the parties involved in the telephone conversation

Phone hacking is the practice of intercepting telephone calls or voicemail messages, often by accessing the voicemail messages of a mobile phone without the consent of the phone's owner. The term came to prominence during the News International phone hacking scandal, in which it was alleged (and in some cases proved in court) that the British tabloid newspaper the News of the World had been involved in the interception of voicemail messages of the British Royal Family, other public figures, and the murdered schoolgirl Milly Dowler.