Here is Yana Grenik - girl scammer from Ukraine. Her tactics is asking money for correspondence. She uses provocative photos to hook you up and of course their favorite trick 'if you're serious, you must show that'... but valid proof is only in money equivalent.
Proof:
Hi! my honey !!
Honey,
here in Ukraine we make very small monies and I can not pay all for
these letters, Oh my Honey, can you help with half of payment
and I pay other half I do not want to lose you my honey but I do not
know what else to do if you serious man you will help us show me
you not like just playing help us stay together i need you !!!
i wait for the answer
kisses
Slava