A problem of content in the digital era is that it is not always possible to identify those responsible for alleged infringement. Even where it is possible, it is not always possible to impact their actions through legal process (they may originate from a foreign jurisdiction or they may have as an ephemeral presence as whack-a-mole). In between the copyright owner and content poster lies the ISP as a pinch point. While the poster may be hard to reach out and touch, the ISP might not.

The DMCA creates a process, more akin to a dance, between copyright holders, Internet networks, and third party content posters when an allegation of infringement is made. In return for being willing to be caught in the crossfire of a copyright dispute, Congress gave service providers immunity for possible copyright infringement liability. [Harlan] [Napster]

There are four possible defenses to liability that deal with transmission, caching, storage, and search engines. In order to be eligible for any of these defenses, a service provider must

• adopt [Corbis Slip at 15 (discussing how detailed policy must be)],
• implement [Corbis Slip at 17 (discussing implementation of policy)], and
• provide notice [Corbis Slip at 16 (discussing quality of notice)]

of a policy for dealing with subscribers who are repeat offenders; [Harlan] [Ellison at 1080] [Corbis Slip at 14 (discussing repeat offenders)] [Aimster] and

• accommodate and not interfere with "standard technical measure" taken to protect copyrighted content. [17 U.S.C. § 512(i)]

For purposes of these defenses, a “service provider” is “a provider of online services or network access, or the operator of facilities thereof.” [17 U.S.C. § 512(k)(1)(B)]. This definition covers a broad range of Internet activities. [Aimster] [Henderickson v. Ebay] [Corbis] [Henderickson v. Amazon.com]

Where the service provider is an educational institution, see 17 U.S.C. § 512(e) which sets forth conditions for treating potential infringers as third parties distinct from the institutions.

Service providers are also immune from liability for wrongful takedowns. 17 U.S.C. § 512(g).

Many ISPs will have immunity, indemnity, and waivers of liablity within their terms of service.

Note that in situations where the service provider does not fall under these provisions or elects not to participate in these defenses, the DMCA gives copyright owners rights to file for injunctions against service providers that would have the same effect as notice and take down. [17 U.S.C. § 512(j)]