Protests took place across the US on Thursday to demonstrate opposition to sweeping National Security Agency surveillance programs.

The events were organised by a newly hatched organisation called Restore the Fourth, named after the constitutionally guaranteed protection against illegal search and seizure under the Fourth Amendment. Rallies and marches took place in San Francisco, Los Angeles, Dallas, New York City, Washington DC and dozens of other US cities.

Ryan Brown, a regional leader for the San Francisco Bay protests who has been co-ordinating with national organisers, said his participation in Restore the Fourth stemmed from concern over excessive governmental power implied by the spying programs. "I see it as ethically disgusting that the government has both the opportunity and the ability … to collect the data on us individually, without a given reason other than quote-unquote 'protecting our freedoms'," he said.

Restore the Fourth describes itself as a "grassroots, non-partisan, non-violent movement", according to its website. Its central demands are to ask Congress to enact reform of the Patriot Act, which has been used as legal justification for the surveillance programs, to call for the formation of a special committee to investigate the extent of the spying programs, and to hold public officials accountable if they are found to be responsible for unconstitutional surveillance efforts.

Protesters rally in San Francisco. Photograph: Justin Benttinen

Many of the individuals behind the San Francisco event had not met before collaborating with one another, said organiser Nick Desaulniers. After proposing a Bay Area protest on Reddit, "a couple people kind of found it, and a Facebook event popped up" Desaulniers explained. He works for Mozilla but emphasised that the company was not involved in organising efforts. "This has been just kind of running with it."

As it gained traction, Brown said, the effort drew support from the San Francisco-based Electronic Frontier Foundation, the American Civil Liberties Union and the National Lawyers Guild.

Brown said before the protest he expected a turnout of anywhere from 300 to 1,000 in San Francisco. Protesters planned to stop outside the office of Senator Dianne Feinstein, who chairs the Senate intelligence committee and had knowledge of the NSA spying activities before they were revealed to the general public. "She did nothing to stop it," said Brown. "We'll be making a point there of what elected officials can do to stop government wiretapping."

In the end, a few hundred protesters marched down Market Street. By the standards of San Francisco, a city with a rich history of activism, the protest was a tame affair. Police officers on bicycles pedalled alongside the crowd, but the mood stayed relaxed and the protest march never strayed from the sidewalk into the street.

While at least one person donned a Guy Fawkes mask, reminiscent of the Occupy movement, and another covered his face with a black bandana, the crowd consisted of a diverse mix of young and old from throughout the Bay Area, including a number of lawyers and tech workers sporting close-cropped hair, button-down shirts, and glasses. It was infused with an element of internet culture. One person held a sign featuring an Internet meme, and at one point, the crowd chanted in unison, "Get your mitts off my bits!"

The march passes the San Francisco Federal Building. Photograph: Justin Benttinen

"I cannot believe we actually have to protest this in the United States," said Jonathan Nelson, who started an organisation called Hackers and Founders to assist Silicon Valley tech entrepreneurs, and said he'd heard about Restore the Fourth online.

Jack Breese, a San Francisco resident who also works in tech, displayed a sign that read "The NSA has TMI", or too much information. "I knew at the very least I had to come out," said Breese, who illustrated his passion for civil liberties by showing off a metal card he was carrying in his pocket inscribed with the text of the Bill of Rights.

Kristen Rudd, a San Francisco resident who attended the march with her husband and two children, said it was the first time she had been to a protest. "We want to see the Fourth Amendment followed by the government," she said, adding that she'd only learned about Restore the Fourth a day earlier, when she read about it online.

A media spokesperson for the national Restore the Fourth organisation, Douglas MacArthur, said Restore the Fourth got under way last month, in response to revelations about the NSA spying programs. That touched off a firestorm of response on social media networks, which in turn gave rise to a decentralised online community, a website, and finally a call to action. "Pretty much everyone met on the internet," MacArthur explained. "Reddit – that's how we all got involved."

National Restore the Fourth organisers generated widespread interest from online audiences when they conducted an Ask Me Anything forum on Reddit, where readers fired questions directly at discussion leaders.

"One criticism we've gotten about the date is that we'd be 'competing' with the celebrations," MacArthur noted in that thread. "But we aren't competing with them. We are integrated with them. The Fourth of July is already about what we're protesting. What better time to fight for your rights or inform others of the need to than when you're already celebrating the ones you have?"