Ok, so many points to this thread.
I'll start at the top: not wanting to hurt women. That's an admirable traight. However, if she really believes in equal opportunity you're almost BOUND to treat her like you would treat a man. Anything else is sexual discrimination.
Next: her address. Ok, well, that's not really so tough. She's your ex's friend right. So there's a chance you could weasle the address out of the ex. Or at least a last name. With the last name you simply start calling all those folks in the phone book and ask for her. If they say "Wait a minute" bingo! Hangup and send the pornos! Just don't go all stalker on her... that's just creepy.
Another good one (do this from a pay phone) is to call the local recruiting office and suggest that she'd like to talk to them in person. (You might have to find a woman to make the call.)
But really, what you could do is ask the ex about the whole thing. Let her hear the message for herself and see what she says. If she defends her friend... well did you REALLY want to date someone that'll stick up for that behavior? If she didn't know, it might let her know what kind of people she's hanging out with.
I've been down the depression road. It's tough because there is the chemical imbalance which isn't something you can just say "Oh, that's ok" But really dude, shit like this little freak calling you... well... is that REALLY so bad? I know it hurts and if you're already depressed it hurts more. But come on... some freak on the phone... does she actually matter? And if she doesn't matter why would what she said matter?
Oh, and the flaming bag of shit on the doorstep is still satisfying. Sure it's old school, even cliche... but damnit man... step in shit or let your house burn down? You're gonna step in the dookie every time.