Donald Trump, arbiter of our nation’s most sensitive intelligence information, hands out his personal cell phone number and urges foreign leaders to call it, the Associated Press reports. At least one foreign diplomat—Canadian Prime Minister Justin Trudeau—has taken the president up on that request.

According to the LA Times, this move breaks diplomatic protocol and raises concerns about the security of Trump’s communications.

News that Trump—who engaged in years-long condemnation of Hillary Clinton’s handling of classified information—is himself very likely a security risk lit up Twitter on Tuesday night.

Users shared deep concerns about the status of our nation’s most sensitive information:

And boy, did they have jokes: