For me, the unment need is intimacy and closeness. I use cyber-sex to try to fulfill those unmet needs when I'm feeling lonely. I don't know if I would go so far as to say I have an addiction, but I know I have a problem.
It's scary, though, thinking about giving up that unhealthy coping mechanism. Because it means those needs could potentially go unmet for even longer. That's what makes it so hard.