Sept. 11 (Bloomberg) — Dan Abate doesn't have diabetes nor is he aware of any obvious link to the disease. Try telling that to data miners.

The 42-year-old information technology worker's name recently showed up in a database of millions of people with "diabetes interest" sold by Acxiom Corp., one of the world's biggest data brokers. One buyer, data reseller Exact Data, posted Abate's name and address online, along with 100 others, under the header Sample Diabetes Mailing List. It's just one of hundreds of medical databases up for sale to marketers.

In a year when former National Security Agency contractor Edward Snowden's revelations about the collection of U.S. phone data have sparked privacy fears, data miners have been quietly using their tools to peek into America's medicine cabinets. Tapping social media, health-related phone apps and medical websites, data aggregators are scooping up bits and pieces of tens of millions of Americans' medical histories. Even a purchase at the pharmacy can land a shopper on a health list.