On Abuse of Emergency Alerts
Or: The RCMP gave me a series of panic attacks tonight and so my second-ever blog post is dedicated to them and the CRTC.
When: July 20, 2023
Where: Galiano Island, BC, Canada
Today I learned more about the Emergency Alert System equivalent that’s built into the LTE (mobile data) protocol than I ever wanted to know. Unfortunately I learned these things because the RCMP (the Mounties 🇨🇦) have insisted on giving me multiple panic attacks tonight. What a great way to spend my last two weeks in Canada, eh? 🙃 So anyway, nerd tangent inbound about how emergency alerts work on mobile phones, and how Canada abuses their system, if that’s the kind of topic you like a lightning talk in text form about!
Right, so. Many of us who live or grew up in the US are probably familiar with the TV and radio alerts that go out when Bad Stuff’s Going Down: growing up in the Midwest for example it was a near-certainty that I’d hear the severe thunderstorm warning and/or tornado watch/warning alerts on FM radio a few times a month all summer. Fast forward to modern day, and of course all this stuff is now digitized because FM radios are basically delegated to use in cars and… that’s about it.
Turns out these alerts are baked into the LTE spec in a system called WEA, formerly CMAS. WEA is high-level summarized here, but basically it’s a special quasi-SMS message (actually some older Android versions literally display them as such) that has a 90-360 character summary of an emergency, and, importantly to this problem today, an alert level.
WEA has a few levels of alert:
Test messages, which can be fully disabled and ignored by users on their devices.
Public Safety and Imminent Threat alerts (two categories, I’m lumping them into one), which is your garden variety severe weather etc. alerts like from our FM radios of yore. 1
AMBER Alerts, which I think everyone from US+Canada will be familiar with but for anyone who isn’t (or isn’t from here), Wikipedia has you covered
Presidential Alerts, which have been used exactly one time EVER in the US: a test in 2018. Otherwise, this is reserved for like, 9/11-caliber stuff, or nuclear attacks, or other society-ending catastrophes.
The important thing to note is that while tests and AMBER alerts can be opted out of completely and while weather alerts and public safety alerts can be either opted out of, or at least silenced/made to respect your vibration/do-not-disturb settings, at an OS level, apparently per the WEA spec, Presidential Alerts cannot. I guess this makes sense to some degree: if there’s a nuke incoming, as much as I personally don’t even want to know, I respect that most folks probably do. 2
So what the hell does this have to do with the Mounties?
Today in BC there was, sadly, an AMBER alert for some presumed-abducted kids, who were last seen in Kamloops, issued by Surrey RCMP. I should have never known about this at all, because I have AMBER alerts disabled on my phone entirely (I’ve been living in remote, far-flung places for the past two years, I’m of no use helping find anyone - hell, this week I’m at anchor somewhere there’s almost no cars at all, and I’m miles from any ferry terminal. There’s barely cell signal - without Starlink, I wouldn’t even be able to work from here).
EXCEPT! Canadian AMBER alerts aren’t filed on phones as AMBER alerts for some godforsaken reason.
You know what they’re sent out as?
NATIONAL ALERTS. YOU KNOW. THE NUCLEAR WARNINGS. THE ONES YOU CAN’T SILENCE. THE ONES THAT PLAY HORRIFYING APOCALYPTIC SOUNDS WHEN THEY GO OFF BECAUSE THEY’RE MEANT FOR THE END OF DAYS. 3
AND THEN THEY SENT OUT SIX OF THEM. (Two in the 3pm hour, one in the 4pm hour, two in the 11pm hour, and one past midnight, before I finally gave up and turned my phone off, scared of my own shadow from all the jump scares in a dark silent boat late at night).
Apparently this is in some way made mandatory by the
which is basically Canada’s FCC. Kinda. I don’t really know all the details,
but some person on Reddit had a bit of a scoop on the whole
That same Reddit post also talks about the only way to disable the alerts: by
adb shell ing into your phone and disabling some system services. Or the good
old fashioned way, which is what I’m choosing today since
adb shell is
inconvenient right now: turning my phone off entirely. Unfortunately, my
phone also happens to be my alarm clock, like many modern humans. My physical
backup clock is out of service (gotta find the power adapter, wherever that
And so anyway, this is why the Mounties might make me log on later than usual to work tomorrow 🙃. And why this part of the LTE spec is absolutely BROKEN: why should any government have the power to induce panic attacks over anything less than the end of days at 11pm, midnight, 3am, whatever?
Thanks for coming to my TED talk about how, somehow, “my cellphone doesn’t make nuclear alarm noises six times a day” is going to be one of the biggest perks about being back home in the US in a couple weeks.
I’ve also gotten these for other reasons: for example to let me know that the area I was standing in was under a likely-unconstitutional curfew somehow effective in negative 15 minutes (?? math how does it work ??) and that I could be subject to arrest if I stuck around. I wasn’t arrested, and the rest is a long story for another day maybe - but do any of us really want to relive 2020 memories? ↩
Another bit of context is that the WEA spec apparently allows geofencing these notifications, which is how, for example, Seattle Police sent that aforementioned “GTFO or get arrested” alert to my phone in 2020, but my friend who lived just up the hill from there had no such alert. Evidently the payload for these things is an XML document that can identify various bounding boxes (not exactly sure how those work, I haven’t dug in yet). ↩
Also, tangentially, these alerts are also geofenced to the entire province, and this is also apparently a Canada-wide problem. Ontario does the same nonsense. BC is… massive. Like, “the entire space between the lower 48 and Alaska, west of the Rocky Mountains” big. And a non-trivial amount of it is made up of islands. So someone nearly 600 miles north of here would have gotten the same 6 alerts I did today about this. ↩