The Department of Homeland Security (DHS) is set to begin compiling social media data on US immigrants next month, including current green card holders and naturalized citizens, BuzzFeed News reports.

DHS quietly published the new regulation in the Federal Register last week, expanding what the agency is allowed to place in an individual's immigration file. As of October 18, the department can collect "social media handles, aliases, associated identifiable information, and search results" on any US immigrant, the Register states.

The DHS also plans to source data from "publicly available information obtained from the internet, public records, public institutions, interviewees, commercial data providers, and information obtained and disclosed pursuant to information sharing agreements." According to BuzzFeed, this surveillance practice could also potentially sweep up data on anyone who communicates with a US immigrant.

The DHS floated the idea of collecting US visitors' social data back in February, and announced in April some tourists could be required to hand over their phones and social media passwords at the border. Two months later, the Trump administration unveiled a new visa survey requiring some applicants to provide every social media handle and email address they've used over the past five years.

"There's a growing trend at the Department of Homeland Security to be snooping on the social media of immigrants and foreigners," privacy and free speech attorney Adam Schwartz told BuzzFeed, "and we think it's an invasion of privacy and deters freedom of speech."

Constitutional concerns aside, there's little evidence that monitoring a US immigrant's social media presence helps uncover threats to national security, BuzzFeed reports. US Customs and Immigration Services tested a program that scraped data on refugees in the US from social media, and found that the practice didn't reveal clear security concerns—even when other security screening techniques flagged an applicant as a risk.

"It's very difficult to successfully use social media to determine what people are going or not going to do," Faiza Patel, co-director of the Brennan Center's liberty and national security program, told BuzzFeed. "People use emojis, they use short form. Sometimes it's difficult to know what something means."