Buy too much Sudafed and you may get a visit from a cop

If you have a runny nose and run to the store to purchase a decongestant, don't be too surprised if a detective shows up at your door shortly thereafter. Ever since a federal law went into effect that regulates pseudoephedrine, tracking systems have begun to pop up in local pharmacies, reports the Associated Press Since the law went into effect in 2006, pseudoephedrine, a key ingredient in the manufacture of methamphetamine, has migrated behind the counter at pharmacies. Customers must show photo ID to buy the decongestant, and the legal limit for purchases is 9 grams per month - roughly the equivalent of two 15-dose boxes of 24-hour Claritin D, or three 10-dose boxes of Aleve Cold & Sinus, or six 24-dose boxes of Sudafed.

Tracking systems such as MethCheck send local law enforcement the buyer's name, address and age with a swipe of a driver's license or state-issued ID card. If a customer is on a list of suspicious persons or he buys more than the legal limit of 9 grams per month, a detective is notified via email.

MethCheck will soon be able to track purchases by neighborhood or street, which would locate areas where meth chemists enlists others in the neighborhood to buy pseudoephedrine. MethCheck will be used at some 7,000 pharmacies in 43 states by next year, said Rick Jones, spokesman for Louisville-based Appriss Inc., which developed MethCheck.

Critics of the tracking software have raised concerns that people with colds or allergies could be suspected of meth production just for buying more than the average amount of cold medicine.

"People's health information - it's intimate, it's personal, it's something people desperately want to keep private," said Beth Wilson, executive director of the American Civil Liberties Union in Kentucky. "For law enforcement to do an investigation, there must be a reasonable suspicion. I'm not sure just the amount of medication justifies that."

Law enforcement counters by saying that the type of evidence from MethCheck only leads to preliminary interviews with police and is not enough to warrant an arrest.

"It's just an investigative tool," said Van Ingram of the Kentucky Office of Drug Control Policy. "During the course of any investigation, you're sometimes going to interview people who aren't guilty of wrongdoing but who are part of the investigative process."

From a Fourth Amendment perspective, there would be nothing wrong with this if the pharmacy customer is truly free to decline the conversation. But if police are authorized to insist or to impede a person's free movement (or take her into custody), there must at least be reasonable suspicion that the person has committed a crime. Does buying too much Sudafed (perhaps because it's on sale) qualify?