Hackers set off Dallas’ 156 emergency sirens over a dozen times

Part of me suspects that there might be something in this related to current events. If I were to spitball ideas about motives and modus operandi, it feels like the kind of thing a state actor would tamper with, and in terms of style I'd gravitate toward looking in North Korea's direction, since it feels like their style.

Why do it? Raising noise with false alarms, desensitizes the intended signal of an alarm, ruining signal-to-noise, as people slack off about responding to alerts. It also serves as a probe to see what an actual outcome would look like. There's no profit (no money), and no incentive to whip emergency responders up into a confused state, for most non-state actors.

Even SWATTING is usually more targeted, with the prank being played on a specific person. Sometimes SWATTING serves to distract the target from something under their control. That doesn't seem to be present here.

North Korea's hacks usually come across as sort of impish in a lot of ways. They seem to like the attention of getting into the news. Messing with something reminiscent of air raid warnings seems to fit the personality of their general profile, given their ballistic missile ambitions. Other state actors in the news lately, probably wouldn't be as interested in domestic civil defense systems in the U.S.

They (whomsoever is responsible) might be motivated to do something like this (if it were a North Korean team) given some of the sabre rattling going around this season. It rings of something that would score points with Dear Leader.

But then again, yeah, maybe this is just the typical sort of "because it's there" hack, and some script kiddie found his way into another cookie jar.

Tbh it might be best to not have protocols for ignoring sirens.

It was pretty eerie walking outside past midnight to clear skies and sirens all around

but it only took about 2 minutes for me to find a tweet about what was happening

Growing up, the audio tone for that signal was etched into my brain over the course of numerous Saturday mornings, when I woke up early enough to hear the tests. This was before cable was normal. Sometimes it felt like the dial-tone-like noise drilled into your ears for a solid 90 seconds.

Example: https://www.youtube.com/watch?v=oOVwgKmzROw

The new sound is even worse (and seemingly longer), and I imagine it's signal (which sounds more like fax machine squelches than an alert noise) has been crafted to prevent incidents like you describe.

Example: https://www.youtube.com/watch?v=Llrkn2ASVNQ

Also, to prevent deliberate piracy, which was something of an urban legend, but with real, known examples, like the Chicago Max Headroom instance:

https://www.youtube.com/watch?v=tWdgAMYjYSs

It's interesting, because I had always thought the noises were intended to capture the interest of viewers, since it sounds like something of an alarm. It never occurred to me that it might be a system-level control signal. Which makes much more sense now, since the tests were called out as tests, and not drills to prompt viewer activity.

It's funny, because after decades and decades of listening to the test drills, on 9/11 I had expected to hear it cutting in, but it was largely absent and unused. The only time I've ever heard it for real, was during weather-related situations like hurricanes.

Most stations have that device configured to only automatically take over air for the most egregious emergencies, with the rest aired on a discretionary basis. You generally only see full auto relays with full auto stations; pretty much every station with a butt in the big seat is wired discretionary, with individual station policy regarding which alerts to rebroadcast. I wouldn't generally retransmit a severe thunderstorm warning, for example, though I repeated every test. To my knowledge, only a Presidential Activation of EAS bypasses everything, and by law there's a book next to every eligible transmitter that describes the procedure for that (it's a bit unique).

For those who don't know, the tones -- which are indeed received from well-known designated primary stations -- come with a textual representation of the bad news, which is printed out on a little receipt-size slip from a box called a EAS-911 (a few vendors make them). One of two things happen next: either the EAS-911 takes over air automatically and rebroadcasts the bad news as it is received, or it is recorded instead and a little button begins blinking to indicate that the device is waiting for you to give it permission to take over air and rebroadcast the bad news. Pretty much everyone with resources is set up the latter way, partially for the very reason mentioned.

The real ugly scenario with the automatic relay stations is when the primary forgets the "I'm done" tones, and then every station in the state plays WGN for an hour. That's happened before. Fines have been levied.

Well, the small stations who don't have a person decided when to play the alerts are typically listening to two larger stations, and it varies which ones they are listening to. So yes, a malicious actor could conceivably do this, but he/she would have to be close enough the antennas and have a transmitter powerful enough to broadcast over the assigned signals.

As others have noted, larger stations generally always have at least one person present who can verify alerts before rebroadcasting them.

EAS is not a perfect system, but it's not the worst in terms of infrastructure weaknesses.

The SAME format has no inherent security to it. Some implementations do some signal processing (thresholding really) to try to mitigate fake messages.

There may be some things that require relatively low security within a high trust environment. For example, fire extinguishers behind glass in a building.

A quick google confirms this. I live in Michigan and there is a discussion here:https://forums.radioreference.com/michigan-radio-discussion-... about the frequencies used for the tornado systems. Not quite sure if they have changed since the post and discussion was made in 2004?

911 systems (alas) get overwhelmed all the time in large cities (for various reasons).