If you're an immigrant in the United States, the government wants to know what you do online.

Starting on Oct. 18, the Department of Homeland Security (DHS) plans to collect social and internet search data on U.S. immigrants, including naturalized citizens and those with a green card.

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A DHS document published on Sept. 18 and recently spotted by Buzzfeed says the government will broaden its collection of online data in a month.

The document says the government will "expand the categories of records" collected "to include ... social media handles, aliases, associated identifiable information, and search results" and will "update record source categories to include publicly available information obtained from the internet ... and information obtained and disclosed pursuant to information sharing agreements."

We reached out to DHS and Customs and Border Protection for clarification on just how the DHS will get "search results," and what "information sharing agreements" implies. The U.S. often shares intelligence information with with other governments, such as the United Kingdom.

"It's becoming very troubling, because where do you draw the line?"

The agency didn't exactly answer the questions, but a spokesperson did write in an email that "this amendment does not represent a new policy." The spokesperson wrote that the agency "has and continues to monitor publicly-available social media to protect the homeland."

"It's becoming very troubling, because where do you draw the line?" asked Bradley Shear, a lawyer with expertise in social media data. "At social media handles? Do you draw the line a being able to open up cellphones? Email accounts?"

For months now, the White House has pushed to check the Twitter and Facebook accounts of people applying for a U.S. visa, and this new set of rules goes beyond even that. More social media scrutiny of international travelers began in the last weeks of former President Barack Obama's administration, when in December of 2016 the government began to ask for the social media handles of anyone applying to the Visa Waiver Program.

Lawyers with expertise in social media and immigration have advised international travelers to the U.S. to — if possible — take secondary laptops and phones when they know they'll have to go through customs. Travelers worried their social data will be searched at the border may want to consider traveling with fewer devices, or deleting data from the devices they carry after they've backed up the information somewhere else.