The subpoena to REI was one of 92 sent as part of HSI’s (Homeland Security Investigations) investigation into the defendants, according to the court filings. Other recipients included social media companies, airlines, telecom providers, a car rental company, and a state employment agency. At least one subpoena sent to an unnamed airline, the filings allege, asked not only for information about a defendant’s past flights, but also requested that the airline give HSI a “lookout notification” about the defendant’s travel in the future

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The subpoenas sent by HSI agents are also known as 1509 customs summons, and are meant to be used to request information related to imports and exports. However, since the start of the Trump administration, WIRED and other news outlets have reported on DHS’s (Department of Homeland Security) attempts to unmask online critics using the legal tool, which can be sent without the oversight of a judge or a jury