ponzi scheme is not to be taken literally. people say it because the people creating currencies benefit at the expense of everyone else, without offering much in return. i know more or less how it works and that is why i say this. the founders of bitcoin have huge stocks of bitcoins, artificially restricting the bitcoin supply to keep the price up. however if that was not the case the supply of bitcoin would be more or less fixed as it gets harder and harder to mine. also there is nothing of value behind a bitcoin, just people's belief it will stay valuable. because of the inherent impossibility to adjust the supply of bitc depending on demand, it cannot ever function as a currency, because its value cant be adjusted for demand. when demand lessens, as is inevitable, investors will lose their money and the major beneficaries will be those who created bitcoin and sold it for dollars.

the only real value it currently offers, is it allows people to dodge tax and launder money. it also enables the criminal economy, with things like drug-ecommerce when the government does not approve (im all for legalisation, btw). so it undermines goverment authority and enables criminality.

i get that i get downvoted because people here believe strongly in privacy and tend to dislike their governments. but i don't. you have to think about how much of your life depends on government authority in order to understand the danger anything that undermines it poses.