For the past few years, Sunnyvale, Calif., has seen a growing number of nightly murders as unwanted guests flock to its downtown area. While these murders don’t necessitate adding deadbolts to residents’ doors, they do encourage prudence when dining outside or walking under trees and other avian perches. Put in plain language, the town is beset by thousands of crows — which, when gathered in a group, are called a “murder.” The crows routinely gather around the city’s Plaza del Sol, a downtown area that houses cafes, restaurants, and a handful of businesses. The birds create a mess wherever they roost, and their collective cawing has shattered the peace of many a morning. Courtesy of iStock.com/subjug In an attempt to disperse the dark avian cloud that has befallen it, the city enlisted a mercenary falconer. When that approach didn’t fly, Sunnyvale turned to boom boxes and lasers. While this may sound like the corvids were being invited to a social event resembling a Rush concert, the combined measures were intended to deter the crows from gathering. The city played recordings of the sounds of crows in distress from the boom boxes in hopes that the sounds would persuade the unwanted guests to leave. Meanwhile, the photonics-based solution — a simple $20 green laser pointer — involved a city worker aiming a laser beam at the trees and power lines upon which the scores of crows perched. The laser pointers have proved to be the most successful method for dispersing the birds so far — at least around Plaza del Sol. The flock still circles high above the city at night. As many photonics engineers can attest, however, there are no magic bullets: Solutions often raise new challenges. And Sunnyvale’s remedy did just that. Local wildlife advocates voiced concerns about the lasers’ potential to blind the birds, and possibly pedestrians. But the feathers of city officials were even more ruffled after a local media outlet erroneously reported that Sunnyvale was planning to issue laser pointers to residents to help in the crow deterrent effort, which prompted the involvement of the Federal Aviation Administration (FAA). Four airports are located near Sunnyvale — in San Jose, Mountain View, Palo Alto, and San Carlos — and arriving and departing aircraft operate at relatively low altitudes in the city’s airspace. Following the media gaffe, the FAA sent Sunnyvale’s mayor a letter expressing its concern about a community vigilante group waving lasers into the flight paths of passenger jets. While a 5-mW green laser pointer is unlikely to threaten the eyes of crew or passengers on planes flying hundreds of feet overhead, the FAA has stringent rules about shining lasers at aircraft. Offenders face being fined by the FAA for amounts up to $11,000 per violation, or up to $30,800 for multiple laser incidents, and could further invite criminal penalties from federal, state, and local law enforcement agencies. Given these potential consequences, Sunnyvale may have to settle for a few murders here and there.