The NSA's mass surveillance programme violates US laws on freedom of speech, alleges a lawsuit begun by the Wikimedia Foundation.
The legal action has been filed against the spy agency and the US Department of Justice (DOJ).
The legal action, co-signed by eight other organisations, seeks to end the NSA's large-scale surveillance efforts.
The Wikimedia Foundation is the non-profit group that oversees the running of the Wikipedia online encyclopedia.
The foundation said it was taking action against the NSA's so-called "upstream" surveillance work which targets communication with people not in the US.
Such spying violates US laws on free speech and those that govern against unreasonable search and seizure, it said.
The scale of the monitoring carried out by the NSA has been revealed in documents made public by whistleblower Edward Snowden over the last two years. Some of those papers show the NSA tapped the net's backbone network to siphon off data. The backbone is made up of high-speed cables that link big ISPs and key transit points on the net.
"By tapping the backbone of the internet, the NSA is straining the backbone of democracy," said Lila Tretikov, executive director of the Wikimedia Foundation, in a blogpost announcing the legal action.
Targeting the backbone means the NSA casts a "vast net" and inevitably scoops up data unrelated to any target and will also include domestic communications, violating the rules governing what the NSA can spy on, said Ms Tretikov.
Information in the Snowden papers revealed that Wikipedia has been explicitly targeted, said the blogpost.
"By violating our users' privacy, the NSA is threatening the intellectual freedom that is central to people's ability to create and understand knowledge," said Ms Tretikov.
In an accompanying editorial published in the New York Times, Wikipedia founder Jimmy Wales said he hoped the lawsuit would bring an "end to the NSA's dragnet surveillance of Internet traffic".
Other organisations joining the lawsuit include Human Rights Watch, Amnesty International USA, the National Association of Criminal Defence Lawyers and the Global Fund for Women.
The NSA and DOJ have yet to comment on the legal action.