New York Times reporter Natasha Singer has extensively covered the data broker industry for the past several years.

Here are some of the key articles but you can find more at https://www.nytimes.com/by/natasha-singer

Jun 16, 2012 | Acxiom, the Quiet Giant of Consumer Database Marketing http://www.nytimes.com/2012/06/17/technology/acxiom-the-quie...

Jul 21, 2012 | Consumer Data, but Not for Consumers http://www.nytimes.com/2012/07/22/business/acxiom-consumer-d...

Jul 24, 2012 | Congress Opens Inquiry Into Data Brokers http://www.nytimes.com/2012/07/25/technology/congress-opens-...

Dec 08, 2012 | Company Envisions 'Vaults' for Personal Data http://www.nytimes.com/2012/12/09/business/company-envisions...

Aug 31, 2013 | A Data Broker Offers a Peek Behind the Curtain http://www.nytimes.com/2013/09/01/business/a-data-broker-off...

Sep 04, 2013 | Getting a Glimpse of Your Own Marketing Data Online http://bits.blogs.nytimes.com/2013/09/04/getting-a-glimpse-o...

Sep 04, 2013 | Acxiom Lets Consumers See Data It Collects http://www.nytimes.com/2013/09/05/technology/acxiom-lets-con...

Dec 23, 2014 | Data Broker Is Charged With Selling Consumers' Financial Details to Fraudsters https://bits.blogs.nytimes.com/2014/12/23/data-broker-is-cha...

Jun 28, 2015 | When a Company Is Put Up for Sale, in Many Cases, Your Personal Data Is, Too http://www.nytimes.com/2015/06/29/technology/when-a-company-...

Pro tip: If you want to avoid giving out your purchase data, pay cash wherever possible.