I had a very bad experience with the USPS money order crapola. 
About 5 years after the guy I sent it to claimed he never got it, his brother
altered the MO and cashed it.  Since I had the original refunded, the Postal
tards came after me.
     When I pointed out that the MO had obviously been altered had been changed> and not been cashed by me, it seemed unfair to hold
me responsible.  They replied it was still my responsibility and that if I did
not repay them, they would garnish my income tax refund.
     To me, the USPS aided and abetted a thief.  They might have just
taken my $125 themselves.  Needless to say I wait patiently for the day
the Postal Service goes Tango Uniform.