Company logos sit on a wall at Google Inc.'s London Campus, in London, U.K., on Monday, Dec. 2, 2013. Both Amazon Inc. and Google Inc. are building large new facilities in the city, with the search giant pledging to employ 5,000 staff in a new office next to the renovated King's Cross railway hub. Photographer: Jason Alden/Bloomberg via Getty Images

Google endorsed legislation on Tuesday that would roll back the National Security Agency's powers, adding its voice to an activist-led day of action.

"Google recognizes the very real threats that the U.S. and other countries face, but we strongly believe that government surveillance programs should operate under a legal framework that is rule-bound, narrowly tailored, transparent, and subject to oversight," Susan Molinari, the company's vice president for public policy, wrote in a blog post.

Molinari said the company supported the USA Freedom Act, a bill sponsored by Rep. James Sensenbrenner (R-Wis.) and Sen. Patrick Leahy (D-Vt.) that would end the NSA's domestic call-tracking program and impose new limits on other forms of surveillance. Google and other tech companies are worried that revelations about the NSA's surveillance activities could hurt their business in privacy-conscious places like Europe.

Google's announcement came on "The Day We Fight Back," an online push to lobby Congress for NSA reform. The protest was organized by a coalition of activist groups, like Demand Progress and the Electronic Frontier Foundation, and popular websites, like Boing Boing and Upworthy.

"We are thrilled that Google is joining untold activists -- nearly 20,000 calls have been placed to Congress already this morning -- in standing up against the NSA's intrusion into our privacy," said David Segal, executive director of Demand Progress. "Winning this fight is going to require a broad coalition of activists, organizations, and businesses, one that is coalescing around today's activism and will persist until we win the fight against mass suspicionless surveillance."

The day is also billed as an effort to honor the legacy of Aaron Swartz, the internet freedom activist and Demand Progress co-founder who committed suicide in January 2013 after being charged under a federal anti-hacking statute. Though he died before leaked information from former NSA contractor Edward Snowden was made public, Swartz was troubled by the extent of the agency's powers.

Google, along with Apple, Facebook, Microsoft, Yahoo, and AOL, had previously signed onto a letter applauding the sponsors of the USA Freedom Act without endorsing the bill outright. Some of those companies recently hired a lobbyist to focus specifically on NSA reform.

Google's endorsement is particularly notable given that it serves as an implicit rebuke to a competing bill sponsored by home state Sen. Dianne Feinstein (D-Calif.), the chair of the intelligence committee, that would codify and expand the NSA's surveillance powers.

The website for "The Day We Fight Back" urges supporters to call Congress and voice their opposition to Feinstein's bill, describing it as a measure that "would allow the NSA to continue to collect telephone records of hundreds of millions of Americans not suspected of any crime."

A Feinstein spokesman did not respond to a request for comment on the day of activism, instead pointing HuffPost to a press release the senator's office sent out in October.