This is a long, detailed and technical post about what information your internet service provider (ISP, called 'BIAS' in this article) can gather about your internet use and sell to the government or other customers. It's written clearly, though, and it should be easy enough for most readers to follow. In a nutshell, here's what you should do to protect your personal information (quoted):
- Switch providers (see below) is at all possible, to one that will not sell your data.
- Use a VPN to protect and encrypt your traffic from your BIAS and to hide your source (your home’s) IP address from others.
- Enable DNS security, use DNSCrypt or DNSSEC and change your DNS provider.
- Use HTTPS as much as possible, install HTTPS Everywhere.
- Be sure to use a device you control as your Internet gateway, so none of the device’s unique identities can be revealed. Setup your own wireless network and replace any provided hardware if possible.
This is fairly comprehensive and not the easiest things for an average home user to set up (corporate users already do most of this, or should). At a certain point these need to be bundled into a 'secure' internet service. ISPs will be loathe to offer such a package. But a market exists.