Carl Icahn is on a roll. He seems to be winning left and right. He hit a home run with his investment in Netflix. He won with Actavis's $25 billion acquisition of Forest Labs

He is now calling for eBay to spin off PayPal. It seems corporate boardrooms across America listen to the activist investor.

That being said, here are three reasons why Carl Icahn won't go activist on Google (NASDAQ:GOOGL) or Facebook (NASDAQ:FB):

Growth stocks are harder to unlock value from
First of all, Google and Facebook are growth stocks. Most of a growth stock's value is in the future. A spin-off or stock buyback for a growth company would not unlock value because there isn't that much value right now.

Stocks are on a roll
Second, these companies are already on a roll. Google is up over 50% over the past twelve months while Facebook is up 150% in the same time frame. The investors of Google and Facebook are probably very happy. Happy shareholders don't want change. 

Founders own the majority of the voting stock
Third, and most importantly, the two companies are controlled by their founders. Even though the founders don't own the majority of the shares, because both companies have dual class share structure, the founders own the majority of the voting rights. So even if Carl Icahn managed to convince all the other shareholders, if Mark Zuckerberg or the Google guys don't go for it, it would be a wasted effort.

The bottom line
Because the Google and Facebook founders have majority voting control, Carl Icahn is not likely to go activist.

I think it is good thing that those founders have majority control.

Founders tend to manage companies for the long term rather than the short term. In technology, where things change very quickly, running a company to meet quarterly numbers when competitors are focused on the long term is pretty dangerous.

A great example of this would be Facebook and MySpace. Because News Corp (NASDAQ:NWS) acquired MySpace, MySpace executives ran the website to optimize profits. They added ads to the site while Facebook did its best to keep ads off. MySpace users didn't like the ads and flocked to Facebook. Facebook is now worth around $170 billion while News Corp sold MySpace to Specific Media for about $35 million.

Having majority voting control also allows the founders to take chances that a normal CEO would not take.

It allowed Mark Zuckerberg to spend $1 billion to buy Instagram, which for all intents and purposes appears to be a great acquisition. Admittedly, this is early in Instagram's monetization stage, but user growth is encouraging.

It allows Larry Page to support Google X, which is working on many innovative products that may pay off big-time. 

While that type of spending would likely put pressure on any normal CEO, having majority voting rights insulates the Google founders and Zuckerberg. It allows those founders to plan for the long term rather than pleasing Wall Street every quarter. It also keeps Carl Icahn from being an activist investor for their stock.

This article represents the opinion of the writer, who may disagree with the “official” recommendation position of a Motley Fool premium advisory service. We’re motley! Questioning an investing thesis -- even one of our own -- helps us all think critically about investing and make decisions that help us become smarter, happier, and richer.