In a troubled world, examples of the goodness among us shine even more brightly than in ordinary times. They should be marked, shared and treasured, because they remind us that sometimes even small actions can make a difference and perhaps even save a life.

Barbara Gusse could have ignored the Amber Alert that flashed across her phone on Saturday afternoon. A bird-watcher, she was outside in bitter cold, feeding the birds that visit her Brooklyn Center yard. Two hours earlier, in north Minneapolis, a mom had just strapped her 1-year-old son into her white Jeep Grand Cherokee when she dashed back in the house for a moment.

In that moment, someone took the car and her son with it.

Thousands saw or heard the alert that followed. But Gusse acted. She had noticed a vehicle idling for "maybe 20 minutes" in a church parking lot across the street. When the alert came across her phone, she grabbed her birding binoculars and checked the license plate. A perfect match. Gusse phoned police and once they arrived, she could hear the boy inside crying.

The Amber Alert system started in Texas in 1996, after the abduction and brutal murder of 9-year-old Amber Hagerman, as a way to use broadcasting systems to alert the public to child abduction cases. Minnesota adopted it in 2002. The system is now used in all 50 states, tapping radio, television, the internet, cellphones and even digital billboards and mobile networks. The system has proved its worth many times since then, and is credited with the recovery of more than 1,000 children since its inception.

And now one more.

But such systems rely on an active citizenry to be the most effective. They need the eyes and ears of concerned citizens, the ones who notice things, who care, who stop what they're doing, for just a moment, to make the phone call.

People like Gusse.

Gusse said she had to do something. "I have nine grandchildren," she told WCCO-TV's Jason DeRusha in a video clip that warmed hearts on Twitter.

But there's another explanation. Gusse is a hero, though she won't admit it. She cared, not just about her grandchildren, but about her community, about a stranger, about a child.

She acted, and that made all the difference.