As part-owners of public companies, we shareholders can vote on everything from CEO pay to proposals on myriad issues. The tip of the iceberg: better corporate governance, full disclosure of political spending, climate change risks, and even animal welfare initiatives are among the many items that can come up for non-binding shareholder votes at public companies.

The increasing emphasis and importance of shareholders' proxy votes have opened a market for proxy advisory firms, which research and offer opinions on how their big investor clients should vote.

However, some corporate interests are taking umbrage at these firms' lack of oversight. It's a fairly hypocritical stance and it should lead investors to wonder what exactly managements and boards are afraid of.

What to do about Dell
In recent years, firms like Institutional Shareholder Services and Glass Lewis have emerged as important voices in proxy voting issues. This year, they have made some pretty significant calls that have reached top headline news.

Just this week, ISS came out in support of a $24.4 billion buyout of Dell (UNKNOWN:DELL.DL), offered by none other than its founder, Michael Dell. He has partnered with private equity firm Silver Lake and is currently vying with Carl Icahn for shareholders' approval for a buyout. Icahn contends that Dell plans to underpay for the company.

Still, ISS is the largest proxy advisory firm, and Glass Lewis and lesser-known firm Egan-Jones have both also backed Dell's offer. These are significant proxy firm blessings.

The Wall Street Journal ran down the many reasons ISS outlined in support of Michael Dell. One of the most compelling is that the founder would take on the financial risk associated with the company's flagging PC business and turnaround efforts. Furthermore, he's the one sticking his neck out and moving to "catch the falling knife," which is not a position investors like to be in. The deal would give shareholders the certainty of a return, as opposed to uncertainty about whether they will continue to see their returns slip at the struggling tech company.

A different kind of proxy battle
Proxy firms' roles in current issues apparently seem threatening to certain groups. Some members of the business community aren't keen on proxy advisory firms' doling out opinions and advice without oversight and regulation.

There are critics from both the corporate interests and political realms who believe the firms should be tracked by the SEC as investment advisors. In March, ISS issued a rebuttal to critics like the U.S. Chamber of Commerce, which had contended that "the [corporate governance] system is broken."

The critics' case might have gained some traction this spring, when it came to light that an ISS employee shared confidential customer voting data with a proxy solicitor. That employee enjoyed lots of goodies like event tickets as payment for the private details on how big shareholders were voting on contentious proxy voting issues.

Still, the SEC did end up pursuing ISS on the issue, and the firm ended up with a $300,000 bill to settle civil charges related to the matter.

Proxies, voting, and perspective
How alarmed should anyone really be by these firms? We already have proof that shareholders don't vote in lockstep with these firms' opinions and therefore aren't automatically following the advisors' advice for lack of any other clue as to what to do. Many commentators are already predicting that the Dell vote will be close.

JPMorgan Chase's (NYSE:JPM) Jamie Dimon faced a high-profile shareholder vote on whether he should retain both the chairman and CEO roles at the megabanker. ISS and Glass Lewis had in fact recommended that shareholders vote for an independent chairman, therefore taking some of his power away. In the end, shareholders did not vote to strip him of the chairman title, despite the fact that Dimon's once-stellar reputation has been tarnished over the last year by the London Whale incident.

Much like investors themselves, proxy advisory services don't even always agree with one another. Earlier this year, ISS and Glass Lewis had competing opinions on Morgan Stanley's (NYSE:MS) CEO pay. Glass Lewis recommended that shareholders vote against James Gorman's pay package, while ISS recommended they vote for it, given a CEO pay decrease that reflected poor financial performance in the past.

In an interesting update regarding Gorman's pay versus performance, at the end of last month, Morgan Stanley finally completed its acquisition of brokerage firm Smith Barney after working on the transaction for four years. Gorman announced, "We went from a period of fragility to healing and now ... one of growth." Given problems that plagued Morgan Stanley last year, maybe shareholders can give credit to heartening signs like this one , and maybe Gorman really is getting the financial giant back on track for the next year. Given the fact that the Smith Barney acquisition is Gorman's strategy to turn Morgan Stanley around and reduce riskiness, success will make his pay less controversial going forward.

ISS and Glass Lewis also had split opinions on Goldman Sachs' (NYSE:GS) CEO pay; again, Glass Lewis recommended a "no" vote, and ISS gave executive pay at the Wall Street giant a thumbs-up. Lloyd Blankfein hasn't made headlines for a while, so shareholders may not have thought much of Glass Lewis' negative recommendation.

However, this week Goldman Sachs shareholders have reason to remember times when the Wall Street giant had reached peak negativity on Blankfein's watch. A former Goldman Sachs employee, Fabrice Tourre, aka "the Fabulous Fab," will go on trial for fraud next week. He's one of the very few bankers who has shown his face in court for his business dealings before the financial crisis, and Goldman is actually footing the bill for his defense in the case.

Who knows what the future holds, and we'll find out how the proxy advisory firms may view Blankfein's pay next year. Obviously, though, shareholders will have to decide, too.

An insult to shareholders, big and small
Proxy advisory firms are simply providing another piece of information to shareholders. They're peddling research and opinions, commodities we all know are an essential part of the marketplace. Regardless of proxy advisory firms, investors can, often do, and should conduct their own research.

Furthermore, institutional investors are theoretically manned with many qualified professionals who can weigh information about how to vote. Although most institutional investors shirked their duties in pushing back against managements for many years, many are now waking up. They are supposed to be looking out for their clients' best interests and making sure corporate managements are doing their jobs.

Meanwhile, even individual investors don't have to view proxy voting decisions as so daunting. Several years ago, corporate governance expert Nell Minow wrote up an excellent, quick-and-dirty primer for proxy voting -- in 60 seconds or less, in fact.

Criticizing the proxy advisory firms sounds a lot like hypocrisy and fear, and even worse, it insults shareholders by implying they can never be trusted to make the "right" decision -- I daresay to some, those "right" decisions mean good for managements' interests.

When we shareholders see that a proxy advisory firm is slamming our stocks, let's weigh the research and opinion and make up our own minds when we vote our ballots. That's what the marketplace is all about.

Check back at Fool.com for more of Alyce Lomax's columns on environmental, social, and governance issues.

Alyce Lomax has no position in any stocks mentioned. The Motley Fool recommends Goldman Sachs. The Motley Fool owns shares of JPMorgan Chase. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.