Just got off the phone with Comcast, there terms of use change depedning on the area you live in.

It is aloud here where I live (low population, wont effect others) but not aloud in say Chicago, so check your area.

Time warner allows it, thats what my parents have had for years, and I have hosted servers there, also had it in texas and was able too.

Verizion, allowed it in my area, you actually need to sign into your account and read your terms of use for them, same this as comcast, if your in a high populated area you cant, low population area you can.

<<<also if you spend the extra $10-20 to upgrade to business class you wont have this issue, any business class is able to host.