One of the most disturbing revelations from whistleblower Edward Snowden is that the National Security Agency copies and searches the contents of virtually every text-based Internet communication that you send overseas or receive from abroad. This includes e-mails, instant messages, search-engine history and the websites you visit. The agency does so whether or not you or the person you’re communicating with has done anything wrong, and whether or not either party is a specific “target” of the NSA. Furthermore, if the agency believes your message contains information relating to the foreign affairs of the United States—in the NSA’s overly broad terms, “foreign intelligence information”—it may hold on to it indefinitely.

This massive, dragnet surveillance is a fundamental violation of the Fourth Amendment, which protects our right to privacy, and the First Amendment, which protects freedom of expression and association. The government is collecting these private communications without any individualized suspicion and without obtaining a warrant from a judicial authority. For these reasons, The Nation has joined the ACLU’s suit against the National Security Agency and the Department of Justice, filed this March in federal district court in Maryland, where the NSA is headquartered. Fellow plaintiffs include the Wikimedia Foundation, Human Rights Watch, PEN American Center, the Global Fund for Women and other civil society, legal and media organizations.

The NSA carries out this dragnet spying, known as “upstream” surveillance, by tapping directly into the Internet backbone—the network of high-capacity cables and switches that carry Americans’ communications with one another and with the rest of the world. Inside the United States, upstream surveillance is conducted under a 2008 law called the FISA Amendments Act (FAA), which allows the NSA to target the communications of foreigners abroad and to intercept Americans’ communications with those foreign targets without a warrant. There are few limits on whom the government may target under the FAA, and those limitations that do exist are weak and riddled with exceptions. Targets can include journalists, academics, government officials, human rights activists, political activists from all over the spectrum and other innocent people who are not connected in any way with terrorism or other criminal activity. Yet the NSA is exceeding even the FAA’s broad authority by spying on everyone, in order to determine who might be talking or reading “about” its targets.

Our lawsuit, Wikimedia v. NSA, is in some respects the successor to Clapper v. Amnesty International USA, a lawsuit that we and others filed in 2008 with the help of the ACLU. Clapper challenged the constitutionality of the FAA on Fourth and First Amendment grounds. In a 5-to-4 decision in February 2013, the Supreme Court accepted the government’s contention that we lacked standing to challenge the law because we could not prove we had been spied on. Snowden has said that the Clapper ruling contributed to his decision to go public with his revelations only a few months later. Thanks to these revelations, as well as government acknowledgments about upstream surveillance over the past two years, we now know far more about NSA surveillance than we did in Clapper. Most importantly, we now know that the NSA is copying and combing through nearly everyone’s international communications—not just those of its targets. This fundamentally changes the standing equation.

The NSA’s massive, dragnet surveillance directly hampers The Nation’s ability to do its business. Our editors and contributing writers routinely engage in sensitive and confidential Internet communications with people in other countries. Those contacts include foreign journalists and other analysts, foreign government officials, opposition figures—including dissidents and, sometimes, members of guerrilla and insurgency movements—academics and human rights activists. The Nation’s research and reporting depends on confidentiality and on our ability to assure contacts that their communications with us—sometimes even their identities—will not be revealed, especially since some of these communications relate to the involvement or alleged involvement of the US government, or its allies abroad, in repression or human rights abuses. Upstream surveillance by the NSA reduces the likelihood that foreign sources will share sensitive information with The Nation’s editors and writers, because they have good reason to fear that their communications will be intercepted by the US government and shared with the repressive regime they live under or with other organizations with which the US government cooperates.

As we celebrate The Nation’s 150th anniversary, we note the magazine’s long, unyielding defense of civil liberties. We are proud, then, to join the ACLU and our fellow plaintiffs in fighting this unprecedented new assault on our freedoms.