Anti-surveillance groups are flooding Congress with calls and emails today in support of legislative efforts that would rein in the powers of the NSA.

The Day We Fight Back Against Mass Surveillance is backed by tech businesses such as Tumblr and Mozilla plus Reddit, the ACLU, Amnesty International and Human Rights Watch.

“The protest is both in his honor and in celebration of the victory over the Stop Online Piracy Act two years ago this month, which he helped spur,” organizers said of Reddit co-founder Aaron Swartz, who committed suicide on Jan. 11, 2013, under  Justice Department prosecution.

“Today the greatest threat to a free Internet, and broader free society, is the National Security Agency’s mass spying regime. If Aaron were alive he’d be on the front lines, fighting back against these practices that undermine our ability to engage with each other as genuinely free human beings,” said David Segal, executive director of Demand Progress, which he co-founded with Swartz.

Anonymous said as of 10 a.m. 9,471 calls had been made and 30,317 emails sent.

The protesters are backing the USA Freedom Act, a bill from original Patriot Act author Jim Sensenbrenner (R-Wis.) meant to “rein in the dragnet collection of data by the National Security Agency (NSA) and other government agencies, increase transparency of the Foreign Intelligence Surveillance Court (FISC), provide businesses the ability to release information regarding FISA requests, and create an independent constitutional advocate to argue cases before the FISC.”

“We understand that the United States was founded upon a Constitution that protects our critical rights and is governed by the rule of law,” the Libertarian Party said in a statement. “Yet, for years, the NSA has exploited secret legal interpretations to undermine our privacy rights — thus chilling speech and activism, and thereby threatening to subvert the very underpinnings of our society itself.”