Common Carrier Question

Folks, I'm working on a graduate policy paper regarding Internet filtering by blocking ASN's or IP prefixes. It is a variation of Net Neutrality, just by a different name. Is anyone in the IANAL field aware of any cases where : a. an ISP successfully defended a common carrier position b. an ISP unsuccessfully defended a common carrier position c. an ISP was treated as a common carrier, even if didn't want to be. d. an ISP was not treated as a common carrier, even if they wanted to. It seems to be way back in the 90's, Compuserve may have been involved in one variation of the above, but the cobwebs are too thick. Replies off list and I will summarize if there is interest. Eric