The most common form of theft historically was larceny by stealth. As property owners and banks took precautions to protect themselves, the methods used by thieves increased in sophistication. Criminals and their opponents, thus, are engaged in a war that has a natural tendency to escalate. Just as automobiles provided increased opportunities for criminal misuse, so, in the future, will computers. As the use of electronic funds transfer systems becomes more widespread, theft by fraud will become more common. Theft by fraud using computer technology has been growing and is aggravated by the lack of effective law enforcement technology and the evolving nature of law covering computer crime. The increased use of credit cards and automatic teller machines since 1975 have greatly increased the opportunities for theft by fraud, and these opportunities have been taken advantage of by criminals. To counter growing credit card fraud, banks published and then computerized lists of stolen and invalid cards. In response thieves resorted to forging cards using discarded carbon copies of receipts. Banks then added holograms to cards to make forgeries more difficult, developed carbonless receipts, and plan to issue cards with invisible account numbers to prevent fraud via telephone orders. Photographs.