(I am particularly concerned with bulk uploads from other services that don't have such policies in place, such as Flickr, because provenance and consent becomes very difficult to trace in that case.)
<climb on favorite hobby horse at first> This is, of course, another side effect of our overly dogmatic fair-use policy, where "it's free like speech as well as free like beer" takes precedence over "it's a good-quality, responsibly-taken image" (I bet we didn't have these problems when fair use was permitted more broadly). Yesterday after reading Sarah's comment about [[Pregnancy]] still leading off with an image of a naked woman, I not only added my voice to the talk-page consensus that such an image was not necessary (WhatamIdoing made the very relevant point that it's not necessary to depict mammary swelling since it does not always occur during pregnancy and, at that range, it's small enough that it wouldn't really be well conveyed in a picture anyway), I looked at the Commons category, not just the well-populated "Nude pregnant women" one but the broader "Pregnant women" one. There are certainly better images like the USDA one that seems to be the favored replacement, but I did notice a lot of the Flickr scrapes, and I really wonder if we should be rewarding exhibitionists just for using the CC-BY license (and Phoebe's complaint also fits in the broader issue of Flickr's apparent disdain for enforcing copyright, to the point that we have a whole page at Commons of blacklisted Flickwashers). This has come up before, with a whole bunch of homemade porn on Commons that was uploaded under PD-self so people could use them to vandalize articles. The vandals have long been blocked but the pictures are still there. </climb down>
Daniel Case