This information can be inadvertently misused, sold, or even stolen.
Timothy authored a software tool that investigates Hypertext Transfer Protocol (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. 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.
Read the full article here - https://www.asc.upenn.edu/news-events/press-releases/your-privacy-online-health-information-serious-risk-abuse