That's not what I mean't. It could be that the situation that causes the absense of fathers might also cause depression, rather than the absense of fathers causing depression. Or it could be some of both. You have to consider all the causal relationships that could explain a correlation.
She didn't actually trace the guy's IP address. What she did was ping tumblr's servers through two different subdomains and seeing that they had the same IP address. Which you would excpect, since they're both tumblr pages. She seems to have taken this to mean that those two users are the same person. If she'd had the sense to test her hypothesis by pinging for example, hallieolivia.tumblr.com, she would have noticed that that has the same IP address too: Pinging hallieolivia.tumblr.com [50.97.1…