It's as if "their immune system to fraud" is weakened, Shadel said.
An AARP study he co-authored last year found that Internet fraud victims had experienced significantly more negative life events in the previous two years than non-victims.
Then he needed money to get materials for his job out of customs.
A car accident was followed by other emergencies that prevented him from coming home — and led to requests for more cash.
She soon got a message from a man who said he was a widowed engineer from Colorado.
Within a week the man calling himself John had captured Joanna's heart with compliments, humor and declarations that she was the one.
So-called romance scams — in which fraudsters smother victims with professions of love then plead for large "loans" to cover invented emergencies — appear to be on the rise, according to federal law enforcement and fraud experts.