It's not certain who launched the attack, let alone why. Dallas emergency director Rocky Vaz would only tell the media that there was a "good deal of confidence" that the attack came from someone "outside of our system," and city spokeswoman Sana Syed indicated that the intrusion happened somewhere in the area.

No matter who's responsible, the incident underscores the importance of locking down public infrastructure. There are certainly alternatives to the sirens (such as mobile alerts and radio), but knocking them out could still put many people at risk if a tornado occurs while the system is down. It also undermines the trustworthiness of these sirens. Why believe them if there's a good chance of a false alarm? Until Dallas and other cities can promise that they're reasonably secure against hacks, it'll be all too easy to second-guess public alerts.