Even if you are in great need of cash loans, turning to a loan shark should never even be considered as an option. Back in the 19th century, America experienced a period with really low interest rates which made small loans unprofitable and lending on the short term was not a common practice. People who wanted to apply for small loans were considered irresponsible. But even back then, one could find a high number of lender that were willing to give that money away but for a huge interest rate. They tricked people into believing they are legit, but never really presented an office where you could meet them.
They would attract customers with steady jobs and families in other word, people with enough responsibilities not to move out of town over night. While people who borrowed money were obliged to sign a contract, this was not actually valid in front of the law. It was more of a proof that the borrower accepted the money.
However, there have been cases where the lender threatened the borrower with legal action. Seeing how the loan was illegal, that could not have been actually possible, but people lacking such knowledge would become really panicked and feared a possible lawsuit. There have also been cases where the borrowers left without a job because their employer found out about the debt and didn't want to work with people with such huge financial problems, involved with loan sharks. In the happy cases where the loan sharks don't turn to violence, they still harass their victims with strange phone calls late in the night, sending out agent to vandalize the borrower's car or home. Feeling shame, desperation, feeling abused and feared of putting his family in danger, the borrowed often collapsed and ended up paying back the enormous debt.