ISP stands for Internet Service Provider. Using an ISP allows your internet history, and even online communications to be tracked and even sold. What this means is everything you do on the internet can be tracked and sold to anyone who wants it by your service provider.
A new bill nullifies U.S. rules that state, “requires telecommunications carriers to inform customers about rights to opt in or opt out of the use or the sharing of their confidential information, adopts data security and breach notification requirements, prohibits broadband service offerings that are contingent on surrendering privacy rights, and requires disclosures and affirmative consent when a broadband provider offers customers financial incentives in exchange for the provider's right to use a customer's confidential information.”
In summary, your ISP doesn’t need your consent to sell your info, does not need to notify you if your data is stolen, and can sell data to whomever they want.
Solutions: VPNs completely hide your information, except that you're using a VPN. HTTPS (to some extent. They can see you're visiting a website but not what page you're on.)