Alert I.D. now has 25,000 subscribers, and has sent 1,000,000 alerts since the program was launched just seven months ago.
"It's pretty incredible," said founder Keli Wilson. "If we tell you that there have been residential burglaries in your area, you can shut the garage door, keep the doors locked, bring your kids in before dark.
"We've had hundreds of emails, thanking us."
Wilson recounts one startling-- but gratifying letter from a military wife and mother whose husband is serving in Afghanistan. She and her daughter moved to Reno and were looking for a home, when their realtor offered space in his own home while they searched for a place of their own.
"The mom was at work and got a flyer for Alert ID," Wilson said. "She signed up and received an alert that a sex offender had moved into their neighborhood. And it was the person she was living with.
"She was living with the sex offender."
Wilson said the woman immediately moved out with her daughter, and thanked the free service for providing her the information they needed to stay safe.
Alert ID is tied in with local, state and federal law enforcement agencies, as well as the Amber Alert system. Subscribers pay nothing to join, and may enter any address-- their home, workplace, child's school or church-- to receive alerts about criminal activity in that area. Other neighbors can log on and share information about what they've seen, as well as any safety concerns they have. They can also communicate with law enforcement.