Catfish?

I have a lot of thoughts, but I will keep it brief. I took particular interest in the title. We have five minutes left in the movie and "Catfish" hasn't been mentioned that I can remember (not that it has to be said, but up to this point "Catfish" isn't very relevant. I could see fishing, but not "Catfish" specifically). I think the title has meaning (as most titles do), but this one is a little troubling. I think it will be revealed at the very end.
Sense that isn't really any significant interest, I will add this: I liked how the film crew left in the shots about Angela's life. Her obsession with facebook has to be some kind of outlet. I'm not justifying her actions, but she has it tough and has to lie to have a compelling, stimulating conversation. Having that kind of contact and conversation keeps people sane. In contrast to that, Abby was introduced right away, and maintained a certain presence throughout; I thought that helped show who Angela's lying was hurting the most.