A proposal to collect travelers’ social media information is under fire from tech companies and civil rights groups, which claim the scheme is half-baked and will lead to a loss of privacy.
The plan, first floated months ago by Homeland Security, calls for visitors arriving in the U.S. to add a “social media identifier” to forms they fill out upon entering the country. The idea is for the government to gain a new pool of data that could make it easier to spot potential terrorists.
The agency’s proposal would not apply to U.S. citizens, and the social media field would be optional for travelers, but that has not quelled the critics.
According to the Internet Association, a trade group that represents companies like Google (GOOGL) and Twitter (TWTR), the plan to collect social media data could lead other countries to demand the same thing.
“This will be true for democratic and non-democratic countries alike, including those that do not have the same human rights and due process standards as the U.S,” said the group in comments on the policy obtained by Politico.
Meanwhile, the advocacy group Electronic Frontier Foundation pointed out how social media identifiers can reveal very personal information about an individuals’ politics, reading habits sexual identity and more. The group also warned that border checks of social media could lead to people censoring themselves online or simply forgoing visits to the United States.
Get Data Sheet, Fortune’s technology newsletter
The EFF along with other groups, which submitted comments to the governments, also observed how the Homeland Security proposal could be a slippery slope. They warned that the government could soon expand it to include Americans returning home—or to begin searching travelers’ devices and cloud data.
All of these are strong points. But the most compelling argument against the social media plan may be the most simple one: it’s hard to see how it would do much to stop terrorism.
In practice, a person intent on attacking the U.S. would be unlikely to disclose their terrorist affiliations on social media simply because they were asked to do so by a form at the border.
The comments by the EFF and Internet Association came in response to an August 22 deadline from the Customs and Border Protection, a division of Homeland Security. It’s not clear when the government will make a final decision about whether to implement the proposed rule.
