I must express my skepticism about this one as well. The article appears sensationalist, with numerous strong statements accompanied by qualifiers, such as "potentially illegally misleading" and "Ponzi scheme if the anecdotes are true." These claims, which rely heavily on anecdotes and hunches, lack factual substance. Some just seem wrong. For instance, the author incorrectly associates low liquidity of notes with fraud, when some financial instruments are simply less liquid. Furthermore, there seems to be a personal bias against Purism, as the investment returns are criticized, even though they are unrelated to the primary topic of questionable legality. The use of emotional language, such as "shady," "sketchy," and "icky," adds no factual value.
Considering the blog's history on HN, my skepticism is heightened. While I'm open to the possibility of Purism's investment solicitation being suspicious — perhaps such a case can be made, I expect an investigative piece to provide more facts and less speculation. It would have been appreciated in this case.