Scamming doesn't always come in the form of money. People can scam others in a myriad of ways. They can put forth a certain persona to sucker people in all the while basing everything off of lies. Eventually the lies catch up. This is not just a prisoner thing. People in the free world do it all the time. Live and learn.
I get tired of people always assuming all inmates live to scam people. No, they're not in there for being upstanding citizens. However, we ALL have a past. Judge not lest ye be judged. You don't want people judging you, right? You have no right to judge anyone unless you are always 100% honest. And no one in this world is.
No one is defending these guys like they're angels. We just like to give people the benefit of the doubt. If you don't want to write then don't. Or you can keep writing and hopefully learn something, about the world and about yourself.