“An analysis of over 80,000 (health-related) web pages shows that nine out of ten visits result in personal health information being leaked to third parties, including online advertisers and data brokers,” stated a press release about a study by a University of Pennsylvania doctoral student Timothy Libert.
Libert built a software tool that examined web HTTP requests initiated to third party advertisers and data brokers. “He found that 91 percent of health-related web pages initiate HTTP requests to third-parties,” stated the press release. “Seventy percent of these requests include information about specific symptoms, treatment, or diseases (AIDS, Cancer, etc.). The vast majority of these requests go to a handful of online advertisers: Google collects user information from 78 percent of pages, comScore 38 percent, and Facebook 31 percent. Two data brokers, Experian and Acxiom, were also found on thousands of pages.”
“Google offers a number of services which collect detailed personal information such as a user’s personal email (Gmail), work email (Apps for Business), and physical location (Google Maps),” Libert wrote in the article. “For those who use Google’s social media offering, Google+, a real name is forcefully encouraged. By combining the many types of information held by Google services, it would be fairly trivial for the company to match real identities to “anonymous” web browsing data.”
According to the study, web users are then at risk of being discriminated against by insurers, employers, retailers, or others who may purchase the aggregated and de-anonymized data. Or their online visit may be automatically treated differently by sites on the web, based on the activities linked to their “anonymous” profile.
Your privacy online: Health information at serious risk of abuse, researchers warn (University of Pennsylvania Annenberg School for Communication press release on ScienceDaily, February 23, 2015)
Libert, Timothy. “Privacy Implications of Health Information Seeking on the Web.” Communications of the ACM 58, no. 3 (February 23, 2015): 68–77. doi:10.1145/2658983. (Brief excerpt)