Frankly, this is one of those technologies that has been around for some time that is suddenly coming to the fore because now it is becoming practical for consumer use and profitable for business to create them.

Previously, you could not scan barcodes without purchasing a device costing several thousand dollars, but now all you need is a smartphone.

The best way to handle these QR codes is to think of them as any other type of Internet-related advertising (which is the entire purpose), with all the caveats and cautions thereunto pertaining. They're somewhat less obnoxious because you actually have to pull out your smart device and perform a scan, unlike say, banner ads and spam, but still indiscriminate scanning has its risks.