Such an unfair practice is illegal pursuant to the Federal Trade Commission Act unless the consumer injury is outweighed by benefits to consumers or competition, or consumers could not reasonably have avoided such injury. The FTC may still consider the public policy criterion, but only in determining whether substantial injury exists. Finally, the FTC no longer considers whether conduct was immoral, unethical, oppressive, or unscrupulous. The FTC has also developed, over time, its definition of deceptive acts or practices. Historically, an act was deceptive if it had the tendency or capacity to deceive, and the FTC considered the act's effect on the ignorant or credulous consumer.
False advertising is often the cause of consumer complaints.
At common law, a consumer had the right to bring an action against a false advertiser for fraud, upon proving that the advertiser made false representations about the product, that these representations were made with the advertiser's knowledge of or negligent failure to discover the falsehoods, and that the consumer relied on the false advertisement and was harmed as a result. In 1911, an advertising trade journal called Printer's Ink proposed model legislation criminalizing false advertisements. Forty-four states enacted statutes based on this model statute. However, because of the difficulty in proving beyond a reasonable doubt an advertiser's dishonesty, prosecutors seldom use these criminal laws. More frequently, the state attorneys general or the FTC regulates false advertising.