According to Costellos's Facebook post she was talking on the phone while walking down a leafy Atlanta, GA. street when three teenagers came up to her.
"One of them grabbed my IPhone," she wrote. "Stupidly I struggled to hold on-to it. But, he was a big guy. And he pulled out a chunk my hair. I let go."
The anchor said she yelled profanities at the kids as they ran away from her laughing adding that all she could feel at the moment was anger.
"I felt no fear at the time, I was just angry. Now I'm angry, shaken and sad. What a lousy life those kids have ahead of them," she said.
After being assaulted Costello found an ABC news report regarding "an uptick in stolen Apple products, dubbed "Apple picking," which consists of thieves stealing iPhones, wiping them clean and selling them for up to $1,000.
Costello then finished her message with a warning.
"Do not talk on your IPhone as you walk down the street," she wrote. "Oh, and let go of the stupid device if someone tries to steal it."
Atlanta police are currently investigating the robbery.