Well, copyright infringement is an unlawful purpose. I don't think you can challenge this subpoena right now. Your argument is with comcast. I've seen people attempt to file motions to quash the comcast subpoena and they've been rejected by the courts because …

Receive a Notice of Action under the Digital Millennium Apr 10, 2014 ISP Subpoena Copyright Infringement Letters - What to do Receiving a copyright infringement letter from your ISP like Comcast, TimeWarner, or COX Communications may be confusing or even scary. You may have arrived at our FAQ page because you or someone in your household received an ISP letter from your Internet Service Provider (ISP) like Comcast or COX Communications informing you they received a Unusual access | DSLReports, ISP Information Obviously lesson learned here but I'm pretty sure Comcast and RIAA doesn't care whether you learn dslreports.com system message This IP address 52.175.223.195 has been blocked for unusual usage Comcast Copyright Infringement? - Comcast XFINITY

Nov 06, 2009

Copyright Alert System - Wikipedia According to Jill Lesser, the Executive Director of the CCI, the CAS's first year was successful as the CAS is "intended to be education based". Lesser indicated that changes for 2014 might include expanding the program to more Internet service providers and also start including other forms of copyrighted media, such as software.

Comcast Threatened With Being “Broken Up” By Congressman

How to Handle a Copyright Infringement Notice From Your ISP