Patent infringement arises when all of the limitations found in a particular claim of a patent are present in a device. For a patented system, the apparatus must have all the required components as delineated in the claim. For a patented method, all of the steps of the method must be performed. Historically, the issue of "who" was the infringer was relatively straightforward because most systems and methods were utilized in discrete, unitary settings. In the modern era, however, particularly with inventions being implemented over the Internet, the issue of "divided infringement" has arisen in two particular contexts.
Timothy R. Holbrook,
The Potential Extraterritorial Consequences of Akamai,
Emory Int'l L. Rev.
Available at: https://scholarlycommons.law.emory.edu/eilr/vol26/iss2/2