Craigslist offers housing opportunities to many people over the Internet. The compensation for a room isn't always financial however.

Certain online ads promise rent-free accommodations for "roommates with benefits," often referred to as "RWB" in listings.

KHOU Ch. 11 conducted a major investigation of the issue and sat down with a Houston area man who has posted a pair of ads on Craigslist looking for a "friends with benefits" roommate situation.

When asked what that meant, the man — who asked that his name not be used and showed up on the screen with his face hidden — got right to the point.

"Well, it means somebody who would be willing to be a sexual partner with you," he said. "It's all about sex."

In exchange for sex, the man promises free rent.

"Go for a roll in the hay," he said. "Get up and go on with our lives. That's all."

While it may be reprehensible, the legality of this kind of arrangement is not entirely clear.

"Some of these may violate the law," KHOU legal analyst Gerald Treece said. He reviewed nearly a dozen Craigslist ads from the Houston area looking for a "roommates with benefits" situation.

"Some of them just get right up and say, 'I want sex for this room,' and that's no different than a solicitation for prostitution," Treece said.

While the practice may seem highly illicit, the commander of the Houston Police Department's Vice Division, Captain Charles Dunn, reveals that stopping the practice isn't easy.

"We can't just throw people in jail for no reason because they may be engaging in some sort of conduct we don't like," Dunn said. "These people may not understand that they're crossing the line."

The man who posted the Craigslist ads seems to be one of those people.

"I never thought of it that way," the man said. "I kind of thought maybe there will be somebody out there who could kind of use some help, and maybe I could help them in some small way and they help me in return."

Treece warns that the reality of the situation could be quite dangerous for all involved.

"It's like swimming in a pool that may have sharks in it," Treece said. "You've got to be really careful on both sides. The guys have to be careful of what women are responding to this, and the women likewise."

Police officials agree that while the situation may sound appealing to some, it could easily end very poorly.

"I've seen a lot of victims of human trafficking, victims of pimps on the street that thought the same thing (that it was a good situation) when they entered into that relationship," Dunn said. "Unfortunately, it turned physical, it turned violent and the next thing you knew, they were being held against their will."

The man who posted "roommates with benefits" ads says that's not what he wants.

"Nobody has to agree to it," he said. "I don't force anybody."

In the first month, the man says he received three responses to his listings, although he has yet to find a "good fit." When asked about the reprehensible nature of his offer, the man agreed that what he is doing is wrong.

"It is reprehensible. It's not the right thing to be doing," he said. "(But) I want to do it."

Watch the full KHOU Ch. 11 investigation: