"Comcast is injecting 400+ lines of JavaScript into web pages" https://forums.xfinity.com/t5/Customer-Service/Are-you-aware-Comcast-is-injecting-400-lines-of-JavaScript-into/td-p/3009551
Good time to remember that the EFF's HTTPS Everywhere extension is a great way to avoid ISPs tampering with HTTP pages: https://www.eff.org/https-everywhere