No worries. **There *are* checks and balances**.

Minority stockholders have a number of options (pun not intended) in terms of litigation.  I start Go-around Corp. and make 737 landing gear.  I sell you a minority stake in Go-around. And after you're onboard, I use the capital to make war on Canada geese. I cover the American east with goose traps, auto-turrets, *I'm wasting all the company's money on a wild goose chase*.  

**You get to sue**.  You get to argue the case that my priorities are twisted, and that I'm not acting in the best interests of the company -- which bottom-lines to *the bottom line*. The judge goes "Yeah, you're not acting the way a company is supposed to, which is the pure unrelenting pursuit of profit (moderated only by an *entirely reasonable* mission statement, which is known for a long time and generally consented to by shareholders), and modulo *modest* deflections toward goals other than profit.    **But these are modest**. 

So for instance Target can give 5% of its profits to the community *when it doesn't have to* - but if it did 90%, the minority stakeholders could sue.  5% is modest, 90% isn't. 

There is now a thing called a LLLC, which is a for-profit business **with a mission**, like a nonprofit. They get to prioritize mission (somewhat) over profit, *but they have to say so up-front* - so as an investor, your eyes are wide open. I could start the Goose-A-Way Landing Gear Company, and our Bylaws state we spend 90% of our profits eradicating Canada geese.  But Boeing doesn't care who builds its landing gear,  so the mission would be like an albatross around our neck - we would fall out of formation with competitors, since business profits weren't being reinvested or paid to investors.  So LLLCs tend to exist for luxury *consumer* products where people are pleased to pay a premium for socially conscious products. 

Here's an example of a lawsuit by minority owners at OP's example company Facebook:
https://www.theregister.co.uk/2019/05/31/shareholders_win_demand_for_facebook_documents_on_cambridge_analytica/

> A court in Delaware has backed investors who want to see internal emails and other documents relating to how Facebook handed data on 50 million users to Cambridge Analytica.
>
> The ruling (PDF) said that shareholders provided enough evidence to support a claim that failures by senior management and board members at the social network may have allowed the illegal data slurp to happen.