Uncle Sam wants to be Facebook friends.
The Department of Homeland Security is proposing to expand the files it collects on immigrants, as well as some citizens, by including more online data—most notably search results and social media information—about each individual.
The plan, which would cover data like Facebook posts or Google results, is set out in the Federal Register, where the government publishes forthcoming regulations. A final version is set to go into effect on Oct. 18.
The plan, reported by BuzzFeed, is notable partly because it permits the government to amass information not only about recent immigrants, but also on green card holders and naturalized Americans as well.
The proposal to collect social media data is set out in a part of the draft regulation that describes expanding the content of so-called “Alien Files,” which serve as detailed profiles of individual immigrants, and are used by everyone from border agents to judges. Here is the relevant portion:
The proposal follows new rules by the Trump Administration that require visitors from certain countries to disclose their social media handles, and allow border agents to view their list of phone contacts.
Those earlier measures alarmed civil rights advocates who questioned whether they would do much to improve security, and worried other countries would introduce similar screening of Americans. In response to the latest effort to collect social media data, the American Civil Liberties Union warned of a “chilling effect.”
Get Data Sheet, Fortune’s technology newsletter.
“This Privacy Act notice makes clear that the government intends to retain the social media information of people who have immigrated to this country, singling out a huge group of people to maintain files on what they say. This would undoubtedly have a chilling effect on the free speech that’s expressed every day on social media,” the group said in a statement.
The new rules are currently subject to a comment period until Oct. 18 but, if they go into effect as planned, they will add yet more data to “Alien Files” that can already contain information such as fingerprints, travel histories, and health, and education records.
Such repositories provide powerful intelligence-gathering tools, but brings potential privacy risks such as government surveillance or cyber-attacks.