Last week, Dan Niles of AlphaOne Capital Partners said AlphaOne is shorting Google [NASDAQ:GOOGL]. Mr. Niles believes that people have been willing to ignore the fact that Google missed revenues, five out of the last six quarters. The stock has been down 5.85% year-to-date and down 14.2% from its 52-week high. There are technical supports at around the $511-$518 levels.

AlphaOne is not the only investment firm that has turned bearish on Google. This week, Bank of America/Merrill Lynch, cut their price target on the stock citing all kinds of reasons, including lower than consensus estimates, increased regulatory risk in the European Union, threats from a strong Apple product cycle, search contract renewal uncertainty from Firefox and Apple, as well as a sharp rise in capital expenditures, wages, etc. Bank of America’s opinion is that it is becoming more expensive to run Google.

Since 2010, Google’s total revenues have been growing at a minimum of a 20% clip, year-over-year, but with several exceptions in which quarters had growth rates that were slightly below 20%. A big shock will come in the fourth-quarter of 2014 where analysts see Google’s revenue growth only at 10.30%.

According to eMarketer, growth of YouTube’s net revenues from worldwide video ads is decelerating at a rate of about 32% year-on-year, from 129.9% in 2011 to a still healthy rate of 65.5% last year. If the trend continues, the estimated worldwide net revenues from YouTube’s video ads this year could be about U.S. $2.61 billion, or a 33.2% increase, from a year ago.

Although the net growth of the video ad revenues from YouTube in the U.S. may decelerate at a slower pace than the revenues worldwide, eMarketer is forecasting the net growth in the video ad revenues from YouTube in the U.S. to be only 16.1% in 2016.

Things might get even tougher for YouTube as Facebook [NASDAQ:FB] just acquired video ad-tech firm LiveRail, for about U.S. $400-$500 million. The fact that YouTube only takes 45% of the total ad revenue and splits 55% with its ad partners, Facebook will be ahead of the game for now, as they will take 100% of their video ad-revenue. Things might change at Facebook in the future as they look for more video ad partners.

Disclosure: No long or short positions in GOOGL or FB