how to stop the catfishing

So in the movie Catfish we watched, we saw how Nev fell in love with this girl he met online, Megan. For months he went on with this online relationship falling deeper in love with this girl he thought he knew. He started to catch on to some things she was saying, he realized that something was fishy about what she was telling him. Not only was she lying about her singing but then she started lying about Abby's (her little sister) art gallery. Wanting to know the truth Nev goes to surprise  her and find out the answers, but it turns out he is the one in for a surprise. Not only did Megan not exist, but it was Abby's mom, Angela the whole time posing as Megan. I had no sympathy because once Nev confronted her about it she tried to blame her life as the reason why she did it, she didn't own up to what she did or apologize. She tried to make excuses. I understand being the mother of three, two of which are disabled, but that does not give you a right to make up a fake person, and fake friends and create this fake relationship which could ruin someones life. She also continued to lie when Nev arrived claiming she had cancer and that Megan was on her way, she then confessed that Megan was in rehab, turns out there is no Megan at all. The part that is really crapy is that she brought her daughter Abby into it and that's not fair to this ten year old girl. I really think people are mentally unstable if they can go on lying straight to people in the face like its nothing about who they are. I know I was not there first hand to witness what Angela did, but from what I have seen I feel sorry for Nev because his life has been changed forever, he now probably has problems with trusting people because Angela played him. Also, I feel sorry for Angela's husband since she could go behind his back and create this fake relationship with someone else. I feel the internet could be really useful when making new friends, or carrying on relationships when not having the ability to do so in person. I think if people took a moment to realize how great the internet could be if it's not misused we could create some great friendships from just a click of a button. I just want to know what could make someone want to catfish another person, and what could be done to stop it from ever happening again. What do you think?