How can you tell a GoFundMe page is legitimate?

How much have you given to individuals on these various types of funding sites?

Did they need money for medical expenses, or are they trying to provide care for a sick child? While a majority of the please are honest, there are some who just want to tug at your heart strings and get your money. 

One New Jersey couple fabricated a story about a homeless man, and they swindled the public into handing over $400,000. They ended up being charged. An Alabama woman faked cancer and raised $35,000. A cat came back from the dead in Florida and its owner raised $6,000.