On Amazon
I was in the middle of writing a post about how I thought this was a poor enactment of a bit of stupid spin (it ain't doing what they say it will any day of the week) and I was checking out whether what they' done was just to remove the rating by whether a book had a 'gay' or similar tag...

And it seems like they might be.

Which put a most evil way of sabotaging this inadequately thought out policy into my head.

It'd need a few more people to check whether this would actually work (it is only a mad-cap thought) but what if people went out and tagged books that haven't any adult content as having it?

I mean, Harry Potter is definitely gay. So is Twilight. So are all those cookbooks by men...

[if one were going to experiment with this I would suggest not picking small sales and midlist authors, who could lose out but go where amazon makes it's money and the bestsellers]

EDIT: really, I have no idea if this has any direct effect (chances are they're using some kind of poorly applied marketing tags to sort the 'adult' content and that those don't show up on the pages) but hey, scientific experiment produces data :)

EDIT 2: http://dearauthor.com/wordpress/2009/04/12/amazon-possibly-using-category-metadata-to-filter-rankings/ I still claim SCIENCE! ::grins::