How is that a ponzi scheme? seems like a bigger proof of stake if anything. Also, you can sell out your drk used for MN at any time you wish.

"Pyramid promotional scheme" means any Masternodes are a plan or operation by which a participant gives consideration for the opportunity to receive compensation which is derived primarily from any person's introduction of other persons into participation in the plan or operation rather than from the sale of goods, services or intangible property by the participant or other persons introduced into the plan or operation.

http://www.azleg.state.az.us/FormatDocument.asp?inDoc=/ars/44/01731.htm&Title=44&DocType=ARS