Comcast

 Comcast  is a service provider that provides internet access to businesses and personal homes.

Home Web Hosting
It appears that Comcast's policies disallow use of their internet service for using a server at your home as your webhost.

Per http://www.comcast.com/Corporate/Customers/Policies/HighSpeedInternetAUP.html

Under "section I. Prohibited Uses and Activities":

"use or run dedicated, stand-alone equipment or servers from the Premises that provide network content or any other services to anyone outside of your Premises local area network (“Premises LAN”), also commonly referred to as public services or servers. Examples of prohibited equipment and servers include, but are not limited to, email, web hosting, file sharing, and proxy services and servers;"

Criticism
Comcast is now injecting javascript to serve it's ads to anyone using the public XFinity Wifi Hotspots per