We have asked our subscribers to answer our question regarding disappearing fans and decided to post their answers.
Here is what you wrote (I will update this post when I get new replies)

I have not seen such thing on my page – Actually since Facebook changed their algorithm I have seen an increase on reach and organic likes.

All my fanpages are OK nothing is missing in. Maybe the missing fans are for the Pages that are merged or cloned couse all over Facebook admins groups are this informations that you concluded.

Yes All pages lost likes in 1 day my 150k page is down to 32k i guess its time to say goodbye to Facebook we need a new social network.

There is no age restriction nor any other restriction. Also all pages have lost likes including my friends it has nothing to do with your page probably many people stopped using facebook and since they didnt log in for a month or 2 Facebook probably deactivated there profile therefore likes removed.

Quite the opposite. I’m gaining fans rapidly!

This hasn’t happened to me, maybe Facebook are removing fake accounts or accounts that have been abandoned.

No so far we are not effect. A slight drop on some pages maybe 5-10%
but not 1/2 of the fans.

So what can we conclude from this? That no one really knows what the hell is going on. Cloned pages are fully cloned, not half way, and you can’t merge a cloned page with a real one, so this theory is out. Disabled accounts? Maybe, but we doubt Facebook would kill so many accounts that quickly. From what we have seen only one page that we have sold has been affected by this, and for that we are sorry. There is just no way we can screen for these types of situations, and Facebook was always (and always will be) risky.