Have we finally grown tired of Facebook? According to Inside Facebook, more than five percent of US users abandoned Facebook in May, that's about six million people who have stopped "liking" the world's largest social network. Six million people jumping ship sounds like a lot, but when you consider that Facebook is on track to hit 700 million users any day now, it's not such a big deal.

But it raises the question: why are users ditching Facebook? Here's a look at 5 possible explanations for May 2011's Great Facebook Exodus.

#1 - Nobody's leaving, the data is wrong

If you ask Facebook, this is one of those instances in which there's smoke, but no fire. A Facebook rep has said that reports such as Inside Facebook's "use data extracted from our advertising tool, which provides broad estimates on the reach of Facebook ads and isn't designed to be a source for tracking the overall growth of Facebook."

So Inside Facebook ran another series of tests using third party measurement services like comScore, Compete, Quantcast and Google Ad Planner, and that data is totally schizophrenic. Some show fast gains, others show slow gains, others report losses and oddly Sony's ranking system shows Pop Tart Cat. Just kidding.

#2 - The privacy issues keep getting worse

Where to start with Facebook's ridiculous string of privacy problems? How about the latest: the opt-out facial recognition software that identifies and tags Facebook users in photos without permission or forewarning.

Facebook apologised, but not for the software. No, it apologised for the software's rocky launch. Now privacy advocates are asking the US government to stop Facebook from using this facial recognition technology.

To put this in perspective, Google's Eric Schmidt says that facial recognition software is too creepy. When Google thinks something too creepy, you know it's way, way too creepy.

Until Facebook users realise that Facebook is a free service that you can cancel at any time and that it therefore owes you nothing in terms of privacy and security, this won't be the last time the site will make headlines for crossing the creepy line.

#3 - Facebook has become too much of a business

Facebook used to be about fun and stuff. It's not that fun anymore.

Lately, when the headlines aren't railing against Facebook's privacy fouls, the media has been reporting on the company's financial concerns and its reported $100 billion valuation. Bor-ing!

Perhaps the Facebook's evolution from startup to unavoidable monstrosity has driven Millennials, a generation typically in favour of entrepreneurialism, into "distrust mode," thereby signalling a widespread call to ditch Rich Uncle Pennybags' once-fun site and move onto other social networking services... which bring us to:

#4 - Facebook is too general, we want specific social metworks

The generalized nature of Facebook is great for those who dig ... stuff. But our social web culture is turning to apps and services such as Instagram for photos, Foodspotting for foodies, GetGlue for multimedia, Soundtracking for music, etc., are catering to those who want a niche.

Sure, these apps are compatible with Facebook news feeds for added sharing capabilities, but they're also building their own specific social networks.

#5 - We're returning to MySpace

I'm sorry, that's comically absurd, but I had to say it.