According to a subpoena obtained by The Intercept, Reddit has until April 14 to provide a wide range of personal data on one of its users, whom U.S. Immigration and Customs Enforcement agents have been trying unsuccessfully to identify for more than a month.

Since President Trump returned to office last year, federal agents have increasingly demanded social media companies reveal the users behind anonymous accounts critical of his immigration crackdown, expressing particular interest in those that identify employees of the U.S. Border Patrol and ICE or share real-time information on enforcement activity. The administration claims the accounts are engaged in doxing and endanger officer safety, but they have also targeted social media users seemingly doing nothing more than expressing anger at the government.

Greene knew of no examples during the recent wave of immigration enforcement-related investigations in which a leading tech company has been called to appear before one of the secret panels. Free speech protections are at their weakest in the context of a grand jury, he explained: The proceedings are not adversarial; their purpose is to permit a prosecutor to file charges.