Earlier quoted context omitted.
The website does not imply "little to no risk." It explicitly states that it's a Ponzi scheme, which clearly means that you're gambling on not being the last one the party.
Yes, but it is not a requirement to hide the fact that it is a Ponzi to be a Ponzi. It still is, if you know about it or not.
>"purported returns"
Disbursements from ponzi.io are not purported to be investment returns or legitimate income of any kind. There are clearly other people's contributions.