I think this is exactly the right complexity level of project for me. It's certainly not too simple, but it's not so complex to be undoable. It also has discrete units, so that I can work on little bits of it, feeling accomplished more frequently.
However (and this is a big however), I can't think of a good use for something like this other than nosiness/stalking. If I actually went through with this and made this nice big tool, I'd want other people to use it. But would I want people to be using it to stalk other people? If it were something that had both good and bad uses, I wouldn't feel any qualms about releasing it (I guess depending on just how bad the bad uses were). However, I can only see bad uses.
Anyone have any thoughts on the matter?