This article by Kira Cochrane is excellent – “Creepshots and revenge porn: how paparazzi culture affects women” in The Guardian:
The story prompts questions about why there is such a market, and therefore audience, for these pictures. As others have pointed out, it is not as though there is any dearth of bare breasts, consensually exposed and shared, on the internet. The answer involves a familiar combination of desire and humiliation. There is an interest in seeing not just any breasts, but all breasts, a sense that female bodies are public property, fair game – to be claimed, admired and mocked…
.. She says the argument goes: “‘You shouldn’t have given those pictures to that person’, or ‘You shouldn’t have been sunbathing in a private residence’, or ‘You should never, as a woman, take off your clothes in any context where anybody could possibly ever have a camera’. That’s been shocking to me, that people aren’t just outraged and furious about this, but they’re actually making excuses for this behaviour, and blaming women for ever being sexual any time, at all.
“Even in a completely private setting, within a marriage – it couldn’t be any more innocuous than the Middleton situation – and yet people are still saying things like: what was she expecting, she’s famous and she’s got breasts, and therefore she’s got to keep them covered up all the time. I do think it’s a rage against women being sexual on their own terms. We’re perfectly fine with women being sexual, as long as they are objects and they’re passive, and we can turn them on, turn them off, download them, delete them, whatever it is. But as soon as it’s women who want to have any kind of exclusionary rights about their intimacy, we hate that. We say, ‘No, we’re going to make a whore out of you’.”