The Trump administration could soon require tourists from dozens of nations to hand over their social media handles before entering the country. Under a proposal from US Customs and Border Protection, the agency would make social media history from the past five years a “mandatory” part of the screening process, as reported earlier by The New York Times.

Right now, travelers from 42 countries — including Australia, France, Germany, Japan, and the UK — can visit the US for up to 90 days without a visa. If the proposal becomes official, visitors would have to include their social media accounts when applying through the Electronic System for Travel Authorization (ESTA) system.

The proposal comes as President Donald Trump continues to clamp down on immigration. In March, the US Citizenship and Immigration Services proposed reviewing the social media accounts of people applying for green cards, US citizenship, as well as asylum and refugee status. Meanwhile, the State Department started asking visa applicants to make their social media accounts public in June. Trump’s fixation on social media isn’t anything new, as his previous administration began requiring some visa applicants to provide their accounts, too.

The CBP’s proposal would also require travelers to submit additional information “when feasible,” including email addresses used over the last 10 years, phone numbers used in the past five years, extensive family member information, and even biometric data. As noted by the NYT, visitors currently need to submit an email address, phone number, home address, and emergency contact information.

The public can comment on the proposal for 60 days.