Having learned 105 minors were rescued and 150 alleged pimps were arrested over the weekend, Betsy James Cooper, executive director of the Heidi Search Center, said the national undercover operation was "really needed."

Now in its seventh year, Operation Cross Country involved federal, state and local authorities in 76 cities, in cooperation with the National Center for Exploited and Missing Children. (See FBI & missing children websites)

The FBI reports at least one child  was rescued in San Antonio, and four suspected pimps here face state and federal charges.    

The Bexar County Sheriff's Office is expected to reveal the results of its sex trafficking investigation at a news conference tomorrow. 

Cooper said the summer months see more young people running away from home.

But she said, "I know runaways don't realize how vulnerable they are out there in the world."

Cooper said often they fall into the sex trade before they know it.

"It's a situation where they don't know they're into it until they're too far into it to get out," Cooper said.

She said the internet and social media also are used by sex traffickers and predators to lure young boys and girls who may be thinking about leaving home.

"You might think your daughter is connecting with another girl across the United States, and it could be a 52-year-old man," Cooper said.

She said parents also should educate themselves about the dangers of sex trafficking.

Cooper said, "It seems so foreign to most people but it happens every day."

For a list of recent stories Jessie Degollado has done, click here.