I will encourage you like I have in several other posts, example https://news.ycombinator.com/item?id=5484850, at this point to contact the FBI. If this was happening over a 56k modem on a phone line it would clearly be wire tapping.
I do not currently see a downside, if you see one let me know.
I've now resorted to using a remote VPN for all of my traffic.
[0]: A reddit post in which I discuss it: http://www.reddit.com/r/self/comments/19zhl6/my_isp_is_injec...