"Always expect the worst out of people. In that way you will never be disappointed and ... sometimes ... pleasantly surprised."
Another favorite of mine, "Do the work!" Meaning, before you part with your hard earned moneys ... do your "due diligence."
Scammers are around because of the healthy population of "marks."
Gees guys ... there are a million aphorisms regarding the subject.
Victims have my empathy but, hardly ever my sympathy. It is easy to avoid such occurrences. the OP's efforts and candidness are a breath of fresh air. Most victims prefer to be unnoticed, allowing the scammers to blithely continue their scams.
Aside: A quiet, non-participating employer, the voter/resident, get what they settle for. If they don't demand great service from their employees, the police, road workers, other first responders, etc. they'll get what ... Well, what they get.