(Reuters) - In the years since people began conducting their lives via electronic devices, courts have forced prosecutors to develop a two-step process for collecting electronic evidence without violating the Fourth Amendment’s strictures against broad searches. In the first step, investigators obtain a search warrant demanding the disclosure of vast swaths of data, often from websites that host information. Obviously, not all of the information is evidence in the government’s criminal investigation. So prosecutors refer to the initial production of information as disclosure, not seizure.

Seizure is the second step. The government sifts through the disclosed data, determines what’s covered by the search warrant, and seizes that evidence. The American Civil Liberties Union, noting that process is codified in the Federal Rules of Criminal Procedure and parallel state rules, calls it “disclose-then-seize.”

The ACLU is worried about what happens to the information that’s disclosed but not seized. In a new filing in the government’s investigation of looting during President Donald Trump’s inauguration, the ACLU has asked Chief Judge Robert Morin of the Superior Court of the District of Columbia to quash a subpoena demanding that Facebook turn over 90 days of records on accounts belonging to three political activists.

The ACLU brief contends that the Facebook warrants would give the government unjustified access not only to irrelevant private information about the activists, such as their medical history and conversations with romantic partners, but also information protected by the First Amendment.

“Government agents would discover a detailed portrait of individuals’ political activities and associations, including their political views and commentary; the pictures and names of individuals who participated in or organized political demonstrations, rallies, dance parties, teach-ins, and other political events; messages reflecting a user’s involvement or affiliation with specific political organizations or groups; and political or organizational strategies for political activism – all regarding events unconnected to January 20,” the ACLU brief said.

The ACLU argues that without safeguards to limit what Facebook discloses or, in the alternative, what prosecutors are permitted to see, the search warrants are “manifestly overbroad,” in violation of the Fourth Amendment. It doesn’t matter, according to the ACLU, that prosecutors will only “seize” information they deem relevant to the investigation. The problem lies in the initial disclosure to the government of private and protected information.

“Permitting government officials to comb through 90 days’ worth of personal messages concerning political activity and associations — some of which are aimed at protesting the policies of the very administration on whose behalf the government officials would be acting in searching Intervenors’ records — is an unjustified invasion of privacy hearkening back to the ‘general warrants’ that the Fourth Amendment was enacted specifically to prohibit,” the brief said.

As you can imagine, this is not the first time that targets of a search warrant for electronic data have advanced the ACLU’s argument. The brief cites a string of cases in which judges have balked at subpoenas calling for broad disclosure of account information. In 2013, for example, U.S. Magistrate Judge John Facciola of Washington, D.C., held that a warrant for information from the Facebook account of a suspect in a shooting at the Brooklyn Navy Yard was overly broad because it demanded disclosures about websites the suspect might have joined. (21 F.Supp.3d 1) That same year, a federal magistrate in Kansas denied search warrant applications that would have required Google, GoDaddy, Verizon, Yahoo and Skype to disclose account records, including emails and instant messages, of a robbery suspect. (2013 WL 4647554)

The Kansas judge, David Waxse, said the warrants were too broad under the Fourth Amendment. “Even if the court were to allow a warrant with a broad authorization for the content of all email communications without a nexus to the specific crimes being investigated, the warrants would still not pass Constitutional muster,” he wrote. “They fail to set out any limits on the government’s review of the potentially large amount of electronic communications and information obtained from the electronic communications service providers.”

Judge Morin, who is overseeing the government’s investigation of violence at the inauguration, has himself set limits on prosecutors in this very case. You may recall the flap earlier this month over a search warrant served on the website hosting service DreamHost, demanding a raft of information about DreamHost client www.disruptj20.org, which acted last January as a clearinghouse for inauguration protests. (One of the three activists the ACLU represents in the Facebook warrant challenge runs disruptJ20’s Facebook account.)

After DreamHost protested the breadth of the warrant, which appeared to require disclosure of information on every visitor to disruptJ20’s website, Judge Morin issued a Sept. 15 order requiring the government to specify a plan to minimize prosecutors’ exposure to extraneous information. (2017 WL 4169713) Though the judge did not specify the safeguards he wants the government to adopt, he emphasized the First Amendment rights of innocent website visitors.

In light of his own DreamHost decision, the ACLU said, Judge Morin should, at a minimum, set parameters in the Facebook account information subject to the search warrants or appoint a special master to review the data before it reaches prosecutors.

Those seem like reasonable protections to me, considering that without them, any of the 6,000 Facebook users who gave a thumbs-up to disruptJ20’s Facebook page will be exposed to prosecutors for the mere act of clicking a like button. Americans have a First Amendment right to associate with protest groups, in real life and on Facebook.