However, Microsoft is now taking steps to limit the spread of the code by sending warnings to people who are sharing it.

BBC: NEWS | Technology | Microsoft targets source pirates

Typically, an attacker will attempt to bypass the username and password system by sending code or characters that confuse the site's programming.

BBC: Sony investigating another hack

He created the genetic algorithm that runs the app after reading programming books and forums, writing the code during his summer vacation and sending mail shots to the tech press to get coverage.

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Link acknowledged that there could be problems enforcing the code if one spammer tried to get a rival shut down by sending junk mail on their behalf.

BBC: NEWS | Technology | Net firms set sights on spammers

Under a change made in March 2005 to the Banking Code, an industry-wide voluntary agreement, lenders were barred from sending unsolicited credit card cheques to customers with a pre-completed loan amount.

BBC: NEWS | Business | Credit card cheques 'under fire'

The young female cashier was texting on her cell phone when I arrived, pointing to the red phone downstairs one must use to call Moneygram and speak to a robot, selecting English or Spanish, whether sending or receiving money, giving the eight-digit confirmation code and personal ID information to release the funds for receipt.

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Some of them rely on technology other than NFC, such as offering services that let people pay for purchases by sending text messages or by scanning product bar codes using a phone's QR-code reader.

WSJ: What's in Your Mobile Wallet? Not Much

"The court was sending a message: Don't rely on the courts to clean up the tax code, '" says Lipton, who chairs the American Bar Association's tax section.

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Giving the consumer an option to scan a QR code which leads them to a website that is not optimized for the device they use to scan it is like sending someone with a broken arm in to get a full-body physical.

FORBES: Why QR Codes Don't Work