US President Donald Trump’s private cellphone is vulnerable to Chinese hackers, according to federal officials who discovered a breach in October 2020. The intrusion allowed eavesdropping on calls involving Trump and other top political figures. In response, some campaign staff abandoned their numbers or used encrypted applications like Signal for voice calls. However, Trump remained unperturbed, with multiple sources indicating he refused to change his phone use despite being warned of the risks for over a decade.
Source: https://www.theatlantic.com/politics/archive/2025/06/trump-private-cellphone-china-hackers/683006