Think about it this way:
You receive heavy narcotics for some supposed chronic pain that you have. But instead of taking the pills, you sell them (this can create quite the residual income for you). Your insurance or medicaid/care pays for the pills, and you also sign a contract with your doctor saying that you will take the medication as prescribed. Selling the pills, or taking them all in one day is a violation of said contract as well as an unnecessary drain on the healthcare system (be it private or government). Currently, the only way to check to see if you are taking them as prescribed, is when you come in to see the doctor, they take your blood and see if there is a level of the drug in your system (easily bypassed by selling all your pills and then saving one for the day of your doctor visit) - this system would negate that process.
I think it's a good idea. They're obviously not going to put this in your Ibuprofin 800mg tablets to make sure that you're taking them, this will be for narcotics and possibly anti-psychotic medications to ensure that they are being used properly.