Well, the documentary that spawned it ("Catfish" as well) involved a woman around 40 that had over a dozen fake profiles, would send Nev who is in his mid twenties I'm guessing (the creator and subject of the documentary) pictures that her little "sister" would paint, care packages, etc. She also claimed that they were opening a gallery for the girls paintings and that she just moved to a horse farm. The girl that this woman was claiming to be was a relative that she no longer had contact with. As soon and Nev and the crew showed up, this woman claimed that the girl was in rehab for alcohol and wasn't around. The ending is pretty eye-opening.
Most of these cases involve people that have low self esteem and are filling some sort of void in their life. Here's a YouTube vides so you can get a gist of what the documentary is all about since I'm not that good at explaining it.
http://www.youtube.com/watch?v=Hq_Ha99qXdc
And the Wiki page for the show:
https://www.google.c...-XAx5B4kXWnhPNg
EDIT: I tried finding a video of the interview at the end of the documentary explaining how they came up with the term "Catfish" but I couldn't find it. If i come across it, I'll definitely post it here.
I'd recommend watching that documentary if you get a chance, it'll really help everyone understand Manti's situation a little bit better.