I'd like more details. Did they really hack the phones? Or use the towers to call the phones with a message.
Hacking every cellphone sounds unrealistic.
Making a call to every phone connected to a tower sounds plausible.
Hacking every cellphone sounds unrealistic.
Making a call to every phone connected to a tower sounds plausible.
But a user would have needed to actively tap on the link to open the stream.
Since the 'beep' is just an audio file, my hunch is that some A/B testing was going on, with most people getting the 'beep' and some getting the message read out.
I imagine that broadcast capability is fully built in, so that mobile phones can replace what we had in the olden days when the government could take over the TV and radio to broadcast whatever they thought was important. I can't remember the last time that the U.S. President spoke to the people in this way, but it used to be fairly common.
I don't think that calling every phone is plausible. In a competitive telecoms market, no provider would build that out. Instead they would keep capacity just above what they know is needed on a daily basis.
Reportedly, some phones have a setting to toggle TTS for emergency alerts...
UK's emergency alert system [1] is based on SMS-CB [2] so it's just test based.
Not because it would be impossible, although the "every phone" is a bit of a stretch given how hard it would be to build an exploit that reliably works on all the messed up versions of Android that vendors put out.
But because if you had a capability like this, you wouldn't burn several full exploit chains just to broadcast a speech.
Doing something on the network side (either compromising existing infrastructure, simply being the infrastructure provider, or providing fake base stations) and then simply calling each phone - sure.
Pushing emergency alert cell broadcast messages with a link to the stream - sure.
Actually exploiting the phones? Nah.
IMHO someone was likely given a task such as "disseminate the message to 100% of the population" and they found a way to claim they accomplished the task (with reasonable credibility).