If you’re going out to tag in Montebello, Calif., consider using a paintbrush. The Los Angeles neighborhood has spent $1 million on an anti-graffiti system that can hear aerosol cans up to 80 feet away. The 25 “tagger traps” employ sound sensors to catch graffiti artists red-(or blue- or green-) handed the moment they deface public spaces, the Los Angeles Times reports.
It's "a lot of money,” a local cop allowed, “but we're spending close to $700,000 a year repairing graffiti”—a figure officials hope its new system will halve within four years. For its part, LA cleaned up 60 million square feet of graffiti last year—but its $7 million cleanup budget can’t be stretched to cover a nasal police state just yet. (More Los Angeles stories.)