This is the study that says Vanguard is one of the most powerful companies in the world for running a bunch of people's 401(k)'s in index funds, right?
The retort is much more relevant:
Most of the companies on the top 50 list are simply investment companies – they aren’t operating companies. (The only obvious example is #50 China Petrochemical.) The enormous size of these companies is simply a reflection of the way most people invest in the public markets, through mutual funds, money funds and other vehicles. Disturbing? Nah. Simply a reflection of the way most people invest in the markets.
http://www.forbes.com/sites/ericsavitz/2011/10/24/retort-the...
They don't have to be "operating companies" to be controlling. Real economic power as the article states.