from some sources I found. and I can draw conclusions

1. Bitcoin Sales and Purchase Fraud between one person and another
2. Bitcoin fraud is committed by a particular group or community
the unknown and clearly known they usually have different specialist tasks in performing bitcoin fraud tasks both online and offline in the real and virtual world.
3. The fraudulent mode of buying and selling bitcoins at online stores or store stores but these errors occur due to the negligence of the person or yourself.

there are more friends