With the recent anti-privacy bill replacing the Obama-era FCC rules, your ISP has been given absolute powers to track your online footprint and sell the information mined to the highest bidder.
For starters, Internet Service providers can monitor your online activity and sell that information to marketers or other third-party firms in the marketing business. These firms then scrutinize your data, evaluate it and use the findings to gain perceptions about your daily life.
For example, when you surf the web searching for “top ranked phones in 2018,” your ISP would regard top-ranked phones as your interest and direct ads related to that query. Nevertheless, the creepy feeling of having targeted ads follow you on the Internet is just one side of the problem. Once your ISP has this personal information on you, you have no control on how else it will use it apart from selling it to marketers.