The Justice Department is demanding that Facebook turn over 
information from three accounts that could provide access to the 
personal details of thousands of activists who expressed interest in 
anti-Trump rallies.
The department obtained search warrants 
targeting three Facebook accounts that were used to organize 
Inauguration Day protests against Donald Trump, the ACLU said late 
Thursday. But accessing those accounts would provide information on 
thousands of other users who "liked" an anti-Trump Facebook page, the 
group explained.
The ACLU’s Washington, D.C., office said in a statement it would fight the enforcement of the search warrants.
"Opening up the entire contents of a personal 
Facebook page for review by the government is a gross invasion of 
privacy," said Scott Michelman, a senior staff attorney at ACLU. "When 
law enforcement officers can comb through records concerning political 
organizing in opposition to the very administration for which those 
officers work, the result is the chilling of First Amendment-protected 
political activity." 
The warrants were issued as part of an
 ongoing case by the Justice Department against people who allegedly 
broke laws while protesting Trump's Jan. 20 inauguration in Washington. Prosecutors have said the website, DisruptJ20.org, was used to organize "a violent riot." 
One search warrant was issued for the DisruptJ20 Facebook page, 
which has since been renamed Resist This, requiring the group’s 
moderator, Emmelia Talarico, to hand over "nonpublic lists of people who
 planned to attend political organizing events and even the names of 
people who simply liked, followed, reacted to, commented o or otherwise 
engaged with the content on the Facebook page," the ACLU said in a 
motion filed Thursday in U.S. Superior Court in Washington.
That could include nearly 6,000 Facebook users who "liked" the page from Nov. 1, 2016, to Feb. 9, 2017.
Two other warrants obtained by the Justice 
Department would require Facebook to hand over "all information from the
 personal Facebook profiles of local DisruptJ20 activists' Lacy MacAuley
 and Legba Carrefour from Nov. 1, 2016, through Feb. 9, 2017.
The warrants demand "all private messages, 
friend lists, status updates, comments, photos, video and other private 
information solely intended for the users’ Facebook friends and family, 
even if they have nothing to do with Inauguration Day," the ACLU said. 
Read more: Feds Demand Facebook Share Information on Anti-Trump Protesters - NBC News