In the chaotic aftermath of Hurricane Katrina, the Bush administration was so eager to compensate for initial bungling that imperiled thousands of Gulf Coast residents, it began passing out cash aid to victims almost indiscriminately. So many people took advantage of this invitation to fraud that federal investigators estimate that 16 percent of the emergency assistance money - about $1 billion - was misspent on bogus victims and duplicate payments, with uses of the funds including football season tickets, divorce lawyers, and - most famously - a sex-change operation. .