The 12 suspects caught in Operation Cyberwild allegedly trafficked in endangered or illegal wildlife, or products made from them, the Los Angeles Times reported.
The operation was a joint effort between the U.S. Fish and Wildlife Service, the California Department of Fish and Game and volunteers from the Humane Society of the United States, the newspaper said.
"This particular operation lasted just a couple of weeks, and during that time, they were able to make 13 buys, or busts, if you will, resulting in charges being filed against 12 individuals and the confiscation of over 46 live wild animals and items made from wildlife parts," said Scott Flaherty, a spokesman for the Fish and Wildlife Service's Pacific Southwest region in Sacramento.
Endangered fish and protected migratory birds were among the many animals recovered live by the investigation, officials said.
"I think that that number, and the short period of time, really speaks to the depth of the problem," Flaherty said. "I think that if the investigation were to go beyond that time, certainly more would have been found."
Paul Todd, program manager at the International Fund for Animal Welfare, says the operation gives just a glimpse into the size of the problem.
"They were just looking at Craigslist and some open Web sites like that. It wasn't exactly clandestine chat rooms and things," he said.
"So if you times that by the whole country times maybe six months or a year, and then if you mix in the harder-to-know things like elephant ivory, you're talking about a pretty robust Internet-based wildlife trafficking operation in the United States."