Your post does confuse me a bit. Yes you should expect and do receive some protection from 'scams' on shares listed on an exchange. That's why press releases are reviewed by the exchange and strange activity investigated by them.

Beyond this you as a shareholder do have certain expectations of ethical behaviour by Management but this is an area that is difficult to enforce unless it's outright fraud or conversion because now you're dealing with enforcement agencies.

What you can't get is protection against making a mistake in your own evaluation of the prospects of any given company. You pays your money and takes your chances. If you want more protection then you buy lower risk bonds/interest bearing certificates.