Last year, it was well documented that President Trump and other high-level officials were cavalierly using mobile devices without regard to the security implications inherent under any circumstance, let alone for someone in public office. This week, The New York Times reported that Trump’s use of mobile phones continues to raise alarms.

Intelligence reports indicate that Chinese and Russian spies (at a minimum) have been eavesdropping on Trump’s calls and intercepting communications between foreign officials.

Wired notes, “A combination of mobile network flaws and insecure telephony protocols makes establishing truly secure calls difficult under any circumstance.” Yet despite being warned repeatedly by aides that his cellphone calls are not secure, Trump has refused to let go of his iPhones.

Mobile phones are not just susceptible to being listened in on, they also function as email devices and can turn out to be an easy way to break into an organization’s network. But the good news according to The New York Times is that, “He does not use email, so the risk of a phishing attack like those used by Russian intelligence to gain access to Democratic Party emails is close to nil. The same goes for texts, which are disabled on his official phones.”

Two iPhones have been altered by the National Security Agency to limit functionality and exposure, according to the Times. One of the two is used for Twitter and apps, the other is used for calls. A third personal phone is essentially the same as most of the ones floating around the world. Trump keeps that phone to store contacts in–something he’s not able to do with the other two.

And while it’s highly unlikely that the president would have access to unsecured Wi-Fi, the vulnerability of phone calls is significant. “Calls made from the phones are intercepted as they travel through the cell towers, cables and switches that make up national and international cellphone networks,” explains The New York Times.

An additional concern with Trump’s use of mobile phones is that official phones are supposed to be swapped out every 30 days–something that Trump has refused to do. Wired points out that this failure to change out his phones could allow malware to remain on his devices for months.

According to Wired, Trump responded to The New York Times article through Twitter, saying, “I only use Government Phones, and have only one seldom used government cell phone” and referring to the Times article as incorrect. Wired writes, “He later found time to add, ‘I rarely use a cellphone, & when I do it’s government authorized. I like Hard Lines.’ Tweetdeck, which lets you view what platform a tweet originated from, shows that Trump sent both of Thursday morning’s missives from an iPhone.”

Also noted in The New York Times article: Mr. Xi and Mr. Putin avoid using cellphones.

Get the full story at The New York Times.