I have no clue what my local government or any such authority could possibly tweet that would be relevant to me. I have not checked their twitter feeds ever and I am none the worse for wear.

For the most obscene example, life safety critical announcements during disasters.

Usually just information about events, road closures etc.

>life safety critical announcements during disasters

There is no way twitter is the sole channel of this over say pushing a text message like they do every other week with a silver alert. Just ridiculous to imagine twitter is some disaster tool.

The mountain passes near me have government-run twitter accounts, and it's usually the fastest way to get rich information on their status during storms.

There is a state government website with some of the same information, but it's usually more coarse (sometimes just the open/close status) and updated less frequently.

Emergency notifications, mainly.

Such as what exactly? I imagine that comes through multiple channels.

Some people have Wifi but not cell phone signal. A single tweet has very robust, existing infrastructure, over the “one email per person in a mailing list” style of email; and SMS is DoA when there’s no cell phone.

I can't imagine a disaster apocalyptic enough to take out cell phone service but somehow spare the power and the internet. Seems like one of those things that you would never have to prepare for and be alright.

There are places that don’t … have … sufficient cell service, as a starting point.

No phone, no TV, only a PC that they sit at logged in to Twitter all day refreshing their feed in case a local emergency comes up?

They have a cell phone on them because they have WiFi in their house, because they have Internet, and they have notifications turned on to their local emergency servers. Since Twitter has a push notifications and a shorter refresh timer, you get messages more regularly that you’ll actually read.

Compare that to email, which you’d get hundreds of messages a day and only care about 3 of them, so you’re not constantly checking.

Edit: dude you live in Australia. Do you know how people in the Bush get their emergency updates that they need to respond to urgently? I bet at least some of them use Twitter or something similar to it. They're not huddled around their weather radio all day (and that doesn't cover everything). Because I had family in rural California and that is exactly how they got theirs. Twitter and Facebook.