As I understand it, there are limitations, it will not be 100% accurate ie: a user could be using a proxy, or VPN, etc.<p>Still, if Comcast is going to throttle specific websites, or charge specific websites for faster connections, can't we use the knowledge that a website visitor is a Comcast subscriber to our advantage?<p>More than that, could Reddit use a protest day to demonstrate what may happen to Comcast customers?<p>For example, instead of a blackout day, Reddit loads slow for Comcast subscribers and only Comcast subscribers.<p>For programmers, here's a possible solution using PHP: http://stackoverflow.com/questions/855967/how-do-i-retrieve-the-visitors-isp-through-php
It's super easy with this: <a href="https://www.maxmind.com/en/isp" rel="nofollow">https://www.maxmind.com/en/isp</a><p>If you're unwilling to pay, then you can get pretty far with their free ASN database: <a href="http://dev.maxmind.com/geoip/legacy/geolite/" rel="nofollow">http://dev.maxmind.com/geoip/legacy/geolite/</a>