Here is a report from the Communications Fraud Control Association (CFCA) about a voice phishing (vishing) attack in the Salt Lake City area. The attackers were making calls to random consumers with messages that their debit cards were closed. The messages included a number to call, which played an announcement that attempted to trick them out of personal information. Here is more information on the attack:
I don't know if Voice Over IP (VoIP) was used to generate the messages or answer the responses, but its a pretty good bet that it was.