Yeah, I never meant it as an "Oh well" kind of thing, but more so what Big D is getting at. I'm not sure what you hope to achieve by finding this person... I'm sure you hope to find closure of some kind, but it seems like this is still absorbing you and even if you do find the person, what then? Tell them that when they were 14 years old or however old they were, that they were a jerk and that it was really mean? I'm absolutely not trying to belittle you in any way, but I genuinely hope that you can find some closure within yourself as that is where it will inevitably need to take place, no matter if you find the other person or not. If you are still spending all your time trying to track down this person then I don't think that the end result will be what you are after.They have probably left it in the past, as some stupid thing they did as a young teenager. I agree it would be absolutely wonderful if they were to own up and apologise but I simply don't think that will make you feel any better about what happened.
For what it's worth, with all the drama that unfolded, if I recall correctly we did make some checks on IP addresses etc. at the time to establish if the user had created a second account to come back to us with but we found nothing.
I'm so sorry to hear how much this has impacted your life, but I do hope you can look towards ways to finding closure within yourself more so than from some confrontation. You know yourself better than I could know you, obviously, but my gut feeling says that the real action needs to take place in your heart and mind, rather than from any confirmation from the other party... whoever they are.
I must admit I always did want to know what happened, though, so I understand that as someone who was far, far closer to the persona of Tiffiekins than anyone else around, you would want to push harder than the rest of us. I'm just concerned, that's all, for yourself and whether it is healthy that you are still trying to track down this person 14 years later.
Good luck, in whatever action you take, though. Remember to put your own health first, though, mental health especially. *hugs*