The little I know and understand of modern technology, coupled with all the reports from people in the know, suggests all out telecommunications are so highly vulnerable to cyber attack of some form or another, we will NEVER be able to rely on it.
Who, and what, is employed by companies like this will actually make little difference, especially if the intelligence authorities monitor it closely, like keeping Boris away from highly classified national security documents!!
Like the internet and the massive flow of data to the huge storage and processing facilities in the States and elsewhere, which rely on under the sea cables to transfer it all backwards and forwards, or whatever it does, it can be physically attacked at anytime. That may not be from humans either, as already there has been a massive undersea avalanche that destroyed all the cables, condensed together, in a canyon that they passed through that caused a worldwide outage a few years back. No doubt the tech guys on here will know all about that