Fraud can be perpetrated on the Internet, as Internet users may be enticed into spending money on fraudulent schemes advertised and perpetrated through the Internet. Pyramid schemes are often conducted through the Internet. Such schemes provide financial incentives to recruit new distributors. They are generally prohibited by law because it is a mathematical certainty that the pyramids will collapse when no new distributors can be recruited. Other crimes or nuisances common on the Internet are unsolicited commercial E-mail, online auctions, "teaser" pages (promises of easy money), and stock scams. Under a relatively new form of fraud, consumers are prompted to download a purported "viewer program" to view computer images for free. Once downloaded, the consumer's computer is "hijacked" by the viewer program, which turns off the user's modem speakers, disconnects the computer from the local Internet provider, dials an international number, and connects the consumer to a remote site. The expensive international costs are charged to the consumer's telephone bill until the telephone is turned off. Crimes through the Internet can stem from high pressure sales, gambling, and child exploitation through E-mail contacts between child users and predators. Twenty-one detailed recommendations are outlined for preventing the latter crime, including parental controls and parental instructions to children in Internet use.