I only know of one person, through a friend, who has done GFM. She was a rogue tenant, refusing to pay rent (eventually found out she did this with previous landlords), held riotous parties upsetting the peaceful neighbourhood - to name but two offences. Poor landlord was working through the eviction process - time consuming and expensive. House got burned to the ground - insurance and fire service both concluded it was the tenant from hells fault. They claimed they lost all their possessions and wanted landlord to pay for it all as they had no renters insurance.
The good news, landlord got rid of tenant, neighbours got peace again.
Bad news - watching local newspaper reporting the case from her perspective and detailing her GFM link - and people paid into it! Extraordinary - in every way this ghastly person was shamelessly living off the backs of others.
My view - donate to registered charities you trust.