WASHINGTON DC – Visitors to the US might be asked to relinquish their social media passwords to border agents as part of an attempt to tighten security checks.

“We want to get on their social media, with passwords: What do you do, what do you say?” Homeland Security Secretary John Kelly told the House Homeland Security Committee on Tuesday, according to NBC News. “If they don’t want to cooperate then you don’t come in,” CNET News.Com reported. 

Twitter, Facebook and other social media sites can offer a wealth of detail about a person, as President Donald Trump‘s prolific tweeting illustrates. Seeking social-media passwords, though, would go a big step beyond seeing what people posted on public profiles to reveal contacts, private postings and private messages.

Kelly, speaking before Congress to address Trump’s immigration ban, said the password request was an idea the Department of Homeland Security was considering. Another, he said, was seeking visitors’ financial records.

Agents might already be reviewing Facebook profiles. One immigration lawyer told The Independent last month that border patrol agents were checking Facebook accounts of those who were being held in limbo after the ban was first put in place.

A judge last week put a temporary restraining order on the immigration ban, which targets all refugees and residents of seven predominantly Muslim countries and has triggered opposition from dozens of tech companies. The fate of the executive order calling for the ban is now in the hands of federal appeals court judges, but on Wednesday Trump defended it and attacked the US judicial system.

This story was published at CNET.Com.