This is the gist of the post I lost:

ALL Islam allows polygamy under a strict set of circumstances that include:

Agreement of existing partner(s)
Guaranteed equality of treatment of wives
Ability to support additional cost burden

Of course in general those that practise polygamy take very little notice of the rules, but then in a free society they'd probably be the ones that have mistresses, having a mistress in an Islamic society is not tolerated in the way it is in the West, social standing would plummet.

My parents families who are largely small scale farmers in rural Pakistan do not practise polygamy, within their communities it's an extremely rare (and declining) occurrence, I believe this to be the case in Islamic societies worldwide (even in ultra conservative countries like Saudi).

Whether multi partner relationships should be afforded the same rights as single partner ones is a huge question but to my mind it's difficult to see why the state should be involved in a group of individuals family structure. I also can't see why being brought up in a multi partner relationship vs an unfaithful one should impact children more, I've known friends whose parents were having affairs, which is worse? Which impacts society in a more negative way?

As regards misogyny there's plenty of that and other ills in the Islamic world, to a greater extent than the rest of the developing world? I don't think so, remember that Sati (http://en.wikipedia.org/wiki/Sati_%28practice%29) is still practised to some extent in India, I'm sure there are plenty of examples of oppression and discrimination that could be brought up from around the world. The sad fact is that even allegedly civilised countries didn't see the need to treat genders or races equally till relatively recently.

I'm not trying to defend polygamy, just saying I can't see a case for government involvement in interpersonal relationships.