Amid growing concerns about the respiratory virus known as the Middle East Respiratory Syndrome Coronavirus, Amazon is warning sellers that using facial recognition to indicate prices on face masks is a no-no.

The SARS-like infection has so far left at least 11 people dead and infected at least 25 people in Saudi Arabia, according to reports. In January, Danish authorities issued a recall of more than 200 face masks because they weren't fit for the job, according to the Associated Press. Now, when a customer searches on Amazon for face masks with "face recognition feature," an option to update the mask's price comes up. Those willing to customize face masks are instead given a price and the option to add another price for a print.

Amazon is sending out a stern reminder not to fall prey to the online juggernaut's inappropriate bidding system.

"Facial recognition face masks are not eligible for Amazon.com Prime Now delivery, and this feature is not available on other products, including spa facial masks or masks with masks for birds or baby's," Amazon said in a statement to CNET. "Facial recognition face masks are illegal in California for a variety of reasons, and this feature violates the rules under the California Consumer Legal Remedies Act, which prohibits sellers from advertising products that are misrepresented or substituted in a manner that is misleading."

Amazon, who has no shortage of financial and competitive rivals, maintains that it is a user of the facial recognition feature only to warn buyers when they're getting into trouble by running afoul of the law.

"The functionality is meant to notify customers when the mask contains a defect that would be relevant to their particular products and the purpose for which they purchased the mask," Amazon said. "We do not use facial recognition face masks to enable price gouging."