Morin pressed the prosecutor about why investigators would want access to the names of users who "liked" certain posts or photos in the lead-up to the inauguration.
"Explain to me the 'likes,' " Morin said, noting that he'd had a tutorial on the ins and outs of Facebook in advance of the hearing.
Borchert said that "likes" of certain posts describing criminal activity could in some instances suggest a person's criminal intent. The vast majority of likes would not be relevant and investigators are not, for instance, interested in "cat pictures." He said his office is "amenable" to some type of "minimization" of the searches.
"There is simply no risk," according to the government's court filing, that investigators could use the warrants "for compiling information about the account holders' political affiliations and private lives."
Sitting in the front row of the courtroom were two of the targets of the search, Lacy MacAuley and Legba Carrefour. The third warrant is for the Facebook page of DisruptJ20, the political organizing group moderated by Emmelia Talarico.
None of the three - all represented by the American Civil Liberties Union - has been charged by the US attorney with Inauguration Day-related crimes.
The hearing raised questions about whether individual account holders could legally seek to block or narrow government searches of information they share on Facebook.
John Roche, a Facebook attorney, said in court that the company is "eager to protect these folks' privacy and their right to engage in political speech."
The company alerted the three users - MacAuley, Carrefour, and Talarico - to the warrants, after the government backed off their request to keep Facebook quiet about the searches.
Morin said he would rule quickly on the ACLU's request to intervene on behalf of the account holders and outline an approach for limiting the searches.