No, they are not. But a very high percentage of them are either scams or insider enrichment schemes, and 100% of them are very risky. A quick review of the SEC filings should be able to identify the ones that are outright scams and enrichment schemes, but too many people ignore their most useful tool - the SEC filings.
If people had actually taken a couple of minutes to read SHMX's SEC filings, they would never have bought the stock and been stuck holding worthless wallpaper.