Leo James Zabala Jr., 25, of Whittier, is charged with using interstate commerce to attempt to induce a minor to engage in illegal sexual activity.
Zabala appeared in U.S. District Court in Santa Ana on Monday and pleaded not guilty.
He was arrested by Homeland Security in October after showing up for a rendezvous with an agent posing as a 14-year-old Huntington Beach girl, according to court documents.
When he was arrested at the Sea Cliffs Village Shopping Center, Zabala had two vibrators, batteries, tangerine-flavored lubricating lotion, and a receipt showing he had purchased the items two hours before the planned rendezvous with "surfrgirlhb," the indictment says.
The investigation into Zabala began in September with a tip to the National Center for Missing and Exploited Children.
Zabala is suspected of placing as many as 380 sex related ads on Craigslist, many of them specifically targeted high school girls, the document says.
The title of the first ad on June 30, 2009, placed by the same poster, read: "?????Any high school girls looking to make extra cash$?"
The body of the post goes on to say: "im looking for a high school girl for sex. I will pay you cash $ for it If your interested e-mail be the following: Pics (these are a must) Location Availability Age Price (how much?)," according to the affidavit.
No actual victims have been identified or confirmed, officials said, but the investigation is continuing.
"We are scrutinizing an array of evidence," said Virginia Kice, an Immigration and Customs Enforcement spokeswoman.
If convicted, Zabala faces 10 years to life in federal prison.