"Those who sell prescription drugs online without a valid prescription are operating illegally, undercutting the laws that were put in place to protect patients, and are thereby endangering the public health, " said Victoria Espinel, US intellectual property enforcement co-ordinator, in a statement.

BBC: US to target fake online pill pedlars

The Ryan Haight Bill--named after an 18-year-old who died from an overdose of Vicodin purchased online in 2001--would make it illegal to sell prescription drugs online without proof of a prescription issued to the patient in person by a doctor.

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The UK medical newspaper GP reported that 33% of the 423 doctors it surveyed said that they had treated, or suspect they had treated, a patient for the side-effects of substandard prescription only drugs purchased online.

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The proposal would give the Food and Drug Administration (FDA) regulatory oversight of online prescription sales as well as the authority to impose fines upon sites illegally selling drugs like Viagra and Valium.

FORBES: Drug wars

Amtech pointed out in a research note that a test Google search of each of the top 10 best-selling prescription drugs at that time turned up a slew of ads for Canadian online drug peddlers like CanadaDrugPharmacy.com and CanadaDrugCenter.com.

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Those results echo another study released in July: The European Alliance for Access to Safe Medicines found that 62% of drugs sold online were fake or substandard and that 96% of the sites operated illegally, displaying fake certifications or distributing prescription drugs without a prescription.

FORBES: Pharma's Black Market Boom