FundersClub carefully vets all their companies; unlike platforms like IndieGoGo (which serves a different purpose), it's a very "hands-on" process with FundersClub ultimately creating an investment vehicle (LLC) for each company they feature. More: https://thefundersclub.com/site/vetting/

That only makes it more confusing. Look at the list of big names: When a big name gets a hold of a company they believe in, they usually take every share they can get for themselves.

Put another way: If someone thinks a company is going to provide a great return, why would they want to share that return with you?

Maybe because it will only provide that great return if it raises sufficient capital, and they can't provide it all themselves, or want to diversify (as you should too).

Due diligence.

Extensive due diligence.

What keeps the fraudsters out of ordinary investing? I'll give you a hint, they're there. Hopefully there will be enough visibility and due diligence to keep them in check.