In fact - it is not. Given the fact that most people don't lie about their georgraphic location much, they can match the approximate address they get from their program, to the location you've given to them. If you've lied, that makes it harder for them to pin you down. If no IP addresses match your given location, they are at a loss and must then utilize a process of elimination. Programs like this, similar to laplink, allow the would-be stalker to use your IP address to trace your computer's unique identification number.
Every computer has one.
Once they have your computer's ID number, they can use your computer as if you were using it yourself. Now of course, I'm talking the relatively sophisticated user who would want to access this information. Most people, in general, are like everybody else engaged in CyberSex. They have jobs, they are relatively normal, have families and have some type of social life away from their computer. They would be mortified to think that anyone else would want to track them down and are quite content to remain anonymous, enjoying private liasons with others who, like them, have found a means to live out fantasies with others.