Visitors to the U.S. under a visa waiver program are being asked by the Department of Homeland Security for information on their social media accounts, a plan that had drawn criticism from civil rights groups for its potential encroachment on privacy.

The U.S. Customs and Border Protection unit of the DHS asked for written comments earlier this year on its proposal that would add to the Electronic System for Travel Authorization (ESTA) and to a form called I-94W the following entry: “Please enter information associated with your online presence—Provider/Platform—Social media identifier,” which visitors can fill optionally.