The social network, which had fast been gaining right-wing users, said that Amazon had conspired with Twitter, but did not provide any direct evidence.

Hours after it went offline on Monday, the social media start-up Parler filed a lawsuit in federal court accusing Amazon of violating antitrust law and asking for a temporary restraining order to prevent the tech giant from blocking access to cloud computing services.

Amazon told Parler over the weekend that it would shut off service because “a steady increase in violent content” on the site showed that the company did not have a reliable process to prevent it from violating Amazon’s terms of service. Amazon said it would ensure Parler’s data was preserved so that it could migrate to a new hosting provider.

Before Parler went dark, technologists also raced to scrape publicly available data from the app, as part of a broader effort to identify those who helped organize and participated in the riot at the Capitol last week.

Millions of people have turned to Parler since the November election and after Twitter and Facebook barred President Trump after the Capitol riot. Apple and Google both kicked Parler out of their app stores last week, though users who already had downloaded the app could still use it. But the app relied on Amazon’s cloud computing technology to work.

Parler’s complaint was dated Sunday, before Amazon suspended Parler. But the suit was not filed with the court until Monday.

On Monday afternoon, Judge Barbara J. Rothstein said Parler had not served Amazon with its complaint, as court rules require, and ordered it to do so by 5 p.m. Pacific time. The deadline passed with no updates on the court docket indicating that Parler had served Amazon in time. Amazon told the court it intended to oppose the suit.

In the suit, filed in the United States District Court for the Western District of Washington, Parler accused Amazon of terminating, not just suspending, its account — and said it should have received 30 days’ notice. It also argued that Amazon violated antitrust law by conspiring with Twitter, a major Amazon customer, to boot Parler just as it was gaining broader appeal. It said it had 12 million users, and “expects to add millions more this week given its growth the last few days.”

Parler did not provide direct evidence showing that Amazon and Twitter coordinated the response. Instead, it pointed to a December news release announcing a multiyear strategic partnership between Amazon and Twitter, and it made references to Twitter’s own challenges policing its content.

“There is no merit to these claims,” an Amazon press officer said in a statement, declining to be named out of safety concerns. Amazon said it served customers “across the political spectrum” and respected Parler’s right to moderate its own content. But after weeks of expressing concerns, Amazon said it had seen an increase in posts that encouraged and incited violence “that Parler is unable or unwilling to promptly identify and remove,” violating Amazon’s terms of service.

Parler said losing Amazon’s services would be a “death knell,” though other platforms popular with the far right and conspiracy theorists, like Gab and 8chan, have recovered after being terminated by hosting providers.

David J. Groesbeck, a sole practitioner in Washington, filed the suit for Parler.

Separately, data of Parler users was posted online in a searchable database on the website ArchiveTeam.org by a lone researcher, who goes by the Twitter alias “@donk_enby.”

The researcher started archiving all Parler posts on Jan. 6, the date of the Capitol riots, but Amazon’s threat to shutter the service sent the effort into overdrive. By Monday, she claimed to have captured more than 99 percent of Parler’s content, including content they had deleted, in a permanent searchable record. The content included posts, images and more than a million videos, some with the geolocation of those who captured and posted video from the Capitol riots.

“Because of how it was obtained, it’s unclear whether the Parler data will be used for prosecution, but there is a lot there that law enforcement can use to build leads,” said Roman Sannikov, director of cybercrime and underground intelligence at Recorded Future.

Security experts said that while the Parler scrape was not a hack, it indicated a security failure. “With any application that is used by millions of users comes a responsibility to safeguard it,” said Alex Holden, of the Milwaukee-based cybersecurity firm Hold Security. “Letting someone obtain a bulk copy of all the posts and videos is irresponsible.”

Parler has advertised itself as not collecting as much data on users as Facebook and Twitter. But Parler’s own privacy policy said it collected users’ Social Security numbers, geolocation, phone manufacturer and carrier, and mobile activities, which may prove critical for law enforcement investigations.

The researcher also discovered that Parler had content moderation tools in place, but apparently did not use them consistently to take down violent extremist content. Parler didn’t respond to a request for comment about the data scraping.