Web hosting firm DreamHost is challenging a warrant to hand over data on all visitors to a site that organized protests during the inauguration of President Donald Trump on January 20 (AFP Photo/MARIO TAMA)

Washington (AFP) - A web hosting firm is fighting a demand by US prosecutors for data on visitors to a site organizing a protest during the inauguration of President Donald Trump in a fresh clash over digital privacy rights.

The firm DreamHost said it was challenging a warrant seeking to identify the visitors of the protest site DisruptJ20, which organized a demonstration against Trump at the time of his swearing-in on January 20.

DreamHost said in a statement Monday that US Justice Department was asking for more than 1.3 million visitor IP addresses, along with email addresses and other data "in an effort to determine who simply visited the website."

DreamHost said the government's request violated the principle of free speech and other rights.

"That information could be used to identify any individuals who used this site to exercise and express political speech protected under the Constitution's First Amendment," the statement said.

"That should be enough to set alarm bells off in anyones mind."

The clash is the latest between US tech firms and law enforcement over user data, and comes one year after a showdown between Apple and the US government over efforts to access the iPhone of the assailant in the San Bernardino attacks.

Civil liberties and digital rights groups rose to defend DreamHost's stand.

Mark Rumold of the Electronic Frontier Foundation warned in a blog post of the "staggering overbreadth of the search warrant," and called the move an unconstitutional effort to prosecute Trump's political opponents.

"No plausible explanation exists for a search warrant of this breadth, other than to cast a digital dragnet as broadly as possible," Rumold said.

"But the (constitution) was designed to prohibit fishing expeditions like this."

DreamHost's legal brief said the company previously turned over data in response to a subpoena on the organizer of the website, but that the additional information sought would "endanger the First Amendment interests of the innocent third parties who viewed or communicated with the website."