We all had a good laugh one hot day in September, when everyone in San Francisco received three or four phone alerts from city officials telling us, “High temps expected” and “drink water.” But since then, sudden tragedies like the North Bay fires and the Las Vegas music festival shooting have shown that those regional emergency alerts are no laughing matter.
In fact, Sonoma County officials are facing heavy criticism for not sending emergency alerts during the outbreak of the Tubbs and Nuns fires (and subsequent evacuations). While they may sometimes be laughable, alerts can save lives.
But who decides when they’ll will be sent? And how are they targeted to recipients in specific geographic areas?
The messages that make everyone’s phones go off at the same time are officially called Wireless Emergency Alerts. They’re limited to 90 characters — though they can be as many as 360 characters on 4G LTE networks — and can be sent out by government agencies or public safety organizations. Even President Trump can send you one if he’s mad that you’re not reading his tweets.
Those Sept. 27 “High temps expected” alerts directed residents to sfdph.org, the website of the San Francisco Department of Public Health. But the alerts weren’t sent by that department. The messages came from a different city hall entity: the San Francisco Department of Emergency Management.
“We have the ability through the FCC to send these messages,” Francis Zamora, director of the Department of Emergency Management External Affairs, tells SF Weekly. “It’s a powerful resource, and one we don’t take lightly.”
Depending on their jurisdiction, agencies can send emergency alerts to an entire city or state, or just an individual neighborhood.
“We can send a message to mobile phone towers in a defined geographic area,” Zamora explains. “If your mobile device is pinging a tower in that defined geographic area, then you will receive the message.”
But the geographic targeting is not completely precise, and alerts sent to San Franciscans may also be received by residents of adjacent areas like Daly City. “We can send a message to all towers in San Francisco, but you can receive a message in Daly City if your phone is pinging a San Francisco tower,” Zamora says.
Local and federal authorities were granted the power to send Wireless Emergency Alerts through a piece of George W. Bush-era legislation called the SAFE Port Act of 2006. But despite the name, text alerts don’t have much to do with the safety and security of ports and harbors. The emergency alert powers were just some extra legislative pork tacked onto the SAFE Port Act. (That legislation also inexplicably includes internet gambling bans that have nothing to do with port safety.)
While it might seem like the government is texting you, Wireless Emergency Alerts are not technically text messages: They make a different sound than text messages, and they use different technology to ensure that all intended recipients get the alerts right away.
Your cellular service carrier has the option of refusing to transmit the e mergency alerts, but most carriers do automatically enroll their customers to receive them.
That said, you can opt out from receiving the alerts if you don’t want them. Alert capability can be disabled in your phone’s settings, though the process varies for different models.
But there is one unfortunate exception: You’re not allowed to disable alerts from the president. So if Trump decides to send everyone Wireless Emergency Alerts instead of tweeting, you’ll never be able to block him.