More than 100 summer camps in the US are using facial recognition technology to help parents catch a glimpse of their kids when they're away at camp.Venture capital-backed Waldo Photos has been selling the service to identify specific children in the flood of photos provided daily to parents by many sleep-away camps. Camps working with the Austin, Texas-based company give parents a private code to sign up. Parents then upload a headshot or selfie of their child to Waldo's system.When the camp uploads photos taken during activities to its website, Waldo's facial recognition software scans for matches in the parent-provided headshots. Once it finds a match, the Waldo system (as in “Where's Waldo?”) then automatically texts the photos to the child's parents.