Who is Cryptoqueen Ruja Ignatova? Why is there multi-million dollar bounty?

Ruja Ignatova who has been accused in a multi-billion-dollar scam has a $4 million bounty on her head. This has been offered by the FBI which has sought the assistance to locate her. She has accused of selling fake cryptocurrency to the customers of ‘One Coin’ of which she is a co-founder.