The Seattle Police Department revealed a unique approach to combatting swatting on Monday that lets current or potential swatting targets register a confidential profile with emergency dispatchers, in case their address is reported in an attempt to use the police as a weapon. “It’s happening at a rate that’s very concerning to our detectives and our first responders,” said Sean Whitcomb, public affairs director at SPD.

Swatting can result from an online dispute, as a way to shake the confidence of another player, simply “for the lulz,” or for spiteful amusement at someone else’s expense. But it’s no laughing matter to those affected or to law enforcement—especially after police shot and killed a man in Wichita, Kansas, in December 2017 during a swatting call.

The Seattle system appears to be the first in the country that can routinely provide information to assist dispatchers, and potentially defuse a situation before it turns lethal—or even threatening. The department posted a body-cam video from before the swatting registration was available showing officers responding to a call in which the responders believed early on that it was likely swatting. (However, officers still had to pursue the call with extreme care in case a legitimate violent situation was underway.)

Swatting false reports aren’t merely pranks—they vary from bomb threats to someone claiming to have shot people to hoaxed hostage situations to a caller pretending to be hiding from a shooter. To recognize a likely swatting, police sometimes have enough information—such as identifying a call originating from a VoIP line or with telltales details—but in many cases they may expect violent and heavily armed perpetrators. Meanwhile the swatting targets can respond with force, not believing or realizing that law enforcement is involved.

“This type of a crime—because that’s what this is—puts everyone at risk, from people who are the targets, to the swatting complaint, to the first responders who are heading to the scene, to people who are living in the immediate neighborhood,” SPD’s Whitcomb said.

Right now, Seattle Police’s anti-swatting service remains a bit of a hack, but one fully supported by the department and its vendor. To protect themselves, Seattle residents needs to register themselves as a company, provide a full address and other information, and then enter “swatting concerns” in a notes field. To develop the service, Seattle Police worked with Rave Mobile Safety, the vendor of a county-wide emergency system platform previously used to provide additional information for first responders about large-scale properties. Companies, schools, malls, and hospitals currently provide information through Rave about a campus layout, locked gates, and other access critical for health, fire, and law-enforcement agencies.

Whitcomb said Seattle Police have made sure that the information provided remains exempt from public-disclosure laws, the same as health details (such as using an oxygen tank) that residents can provide a separate Smart 911 system consulted by EMTs and other emergency medical staff. If swatting registration were subject to public disclosure, it would obviously run counter to its intent and endanger people.

While registering to defend yourself against what sounds like a prank might sound absurd to some, the head of the Seattle Online Broadcasters Association told Geekwire that two members of the streaming and broadcasting community had received death threats last week and been “doxxed,” or had personally identifying information posted online.

Swatting gets deployed against a wide array of targets, including as targeted harassment by extremists in social movements, such as the reactionary GamerGate, and against prominent pundits and politicians from left to right. Right-wing commentator Erick Erickson was swatted in 2012 as well as Democratic House member Katherine Clark in 2016—after she’d sponsored the Interstate Swatting Hoax Act, to make a false emergency report a federal crime.

No agency keeps track of the total number of swatting incidents, but they are numerous enough that departments across the country (and in some other nations) have to deal with it routinely. Calls that end without incident rarely make the news, but Wikipedia and articles at several sites list a portion of reported swatting against celebrities and other people.