Be careful, if a weird russian approaches you with a ransom request.
I had a guy approach me and asking $5000 via LR, when I said no he said he'd attack again, and generated a ddos. His ddos was different from what I had before, so I'd guess lots of people are seeing in bitcoin an opportunity to make money.
I strongly recommend against doing anything those guys request, and even replying may be a bad idea, just click "spam".
Any chance you could post those messages for the world to see?