SAN DIEGO -- Virtual worlds exist online, and companies like Google and MTV have one.

However, some cyber crime experts say there's one cyber universe that's so advanced it's a danger for children.

Second Life is a 3D virtual world that was created by Linden Labs. Its users, or residents, create the world.

"In Second Life you can create things, create objects, create rooms, trees—mimic what your house would look like," says Lt. Joseph Rampolla, who works for the Park Ridge Police Department in New Jersey and has dedicated much of his time on understanding this virtual world.

On Second Life people create different lands and make alter egos, or avatars. Once on the site, you can navigate your avatar to different areas. There are positive areas in Second Life, and real life businesses and universities use this site to educate or advertise. Reuters has a site on Second Life, for example.

In this virtual world, users can turn so-called 'linden' dollars into real dollars by having their avatars perform jobs or chores in certain worlds. Rampolla says some people have quit their real world jobs to make money on Second Life.

"It's very realistic, and every day more realistic," he says. "They have an edge on virtual worlds. The transfer of virtual dollars to real dollars is a big component."

Lt. Rampolla is quick to add that while this virtual world may be innovative, it can be incredibly dangerous for children. There are rooms in Second Life that have been created by its users that are beyond pornographic.

"There is sexual abuse, torture, rape," he says.

There's a site called "Suicide for Fun." Forms of bestiality exist, and so does age play, Rampolla warns.

It's very possible that what appears to be a 10-year-old avatar could be controlled by a 50-year-old man.

"I would say 50 percent of people are in Second Life for some kind of sexual interaction," says Rampolla.

There are rooms created specifically for drugs, where your avatar can uncover information about different kind of narcotics and then practice making or using them.

"It's a training ground on how kids can harm themselves," says Rampolla.

Second Life is becoming more popular. According to its Web site, millions of residents have flocked to this world.

Linden Labs says members are actively monitored, and "suspected minors must provide proof of age, and if it's not provided, they are blocked from the adult Second Life grid."

However, the I-Team went on the site and found how easy it is to become a part of this world. We simply clicked we were older than 18, and immediately we were able to enter. There was no proof needed.

Linden Labs declined an on-camera interview with the I-Team instead sent a statement saying, "We are consistently and constantly striving to make our platform even safer and to prevent minors from accessing age inappropriate content. We certainly do not condone the provision of violent or sexual images to children."