. >> lynn szymoniak: in my mind, this is an absolute intentional fraud. >> pelley: lynn szymoniak ishting foreclosure. and while trying to save her house, she discovered something we did not know. back when wall street was using algorithms and computers to engineer those disastrous mortgage-backed securities, it appears they didn't want old fashioned paperwork slowing down the profits. this was back when it was a white hot fevered pitch to move as many of these as possible. >> szymoniak: exactly. when you could make a whole lot of money through securitization. and every other aspect of it could be done electronically-- you know, key strokes. this was the only piece where somebody was supposed to actually go get documents, transfer the documents from one entity to the other. and it looks very much like they just eliminated that step altogether. >> pelley: szymoniak's mortgage had been bundled with thousands of others into one of those wall street securities traded from investor to investor. when the bank took szymoniak to court, it first said that it had lost her documents, including