Phone scams will be deemed as fraud, since the fraudsters are trying to get money from the victims with promises that have no intention of being fulfilled.
But let's say that a man and a woman are chatting over irc or msn and the man sweet talks the woman and gets money from her by telling her some sob story. Is this considered a scam if the woman reports later or can the man claim that she gave him the money willingly and voluntarily? Is it therefore a crime?