When a computer dials you up and greets you with an prerecorded message, you've been robo-called. Robocalls, the unenthusiastic way to describe an automated call on behalf of a candidate, are exempt from the Federal Do Not Call Registry.
Under a 1991 law, the dinner-interrupting robots must tell you who is sponsoring the calls as well their return phone numbers. McCain, a victim of smear calls in 2000, defended a recent surge in campaign robocalls which warn voters that they "need to know that Barack Obama has worked closely with domestic terrorist, Bill Ayers, whose organization bombed the US Capitol, the Pentagon, a judge's home, and killed Americans." On Sunday, he said: "These are legitimate and truthful and they are far different than the phone calls that were made about my family."
Back when Mitt Romney was hitting up voters with automated calls the majority of you said you'd consider not voting for someone who made a robot call you. Since most Americans despise impersonal, often negative, phone calls, it's a surprise candidates use them.