About a month ago Alia Magda Elmahdy, a 20 year old student from Cairo, posted a photo of herself online. In the full-length black and white image she appears naked apart from a pair of stockings. Her shoes and a bow in her hair are highlighted in red. In the context of the internet, a medium notoriously replete with naked female flesh, there's nothing especially remarkable about the image, even allowing for her nationality. But Elmahdy chose to display her body as an avowedly political gesture. She has described her action as a protest against sexism in Egyptian society and a demand for artistic and sexual freedom. Here's what she wrote on the blog:

Put on trial the artists' models who posed nude for art schools until the early 70s, hide the art books and destroy the nude statues of antiquity, then undress and stand before a mirror and burn your bodies that you despise to forever rid yourselves of your sexual hangups before you direct your humiliation and chauvinism and dare to try to deny me my freedom of expression.

According to the New York Times, "it is hard to overstate the shock at an Egyptian woman's posting nude photographs of herself on the Internet in a conservative religious country where a vast majority of Muslim women are veiled and even men seldom bare their knees in public."

That may be an exaggeration. But certainly everything about Aliaa Magda Elmahdy seems calculated to annoy Egypt's increasingly powerful Islamists -- and embarrass moderate secularists. Not only is she unafraid to break taboos by posing naked, she describes herself as an atheist and lives openly with a boyfriend who himself was imprisoned for writing things critical of both Islam and the former president, Hosni Mubarak. In an interview with CNN this weekend she defended gay rights, spoke openly about her sex life and called for a "social revolution", declaring that "women under Islam will always be objects to use at home."

If provocation was her aim then she has succeeded, though at considerable personal cost. Her blog post -- which also displays several other images, including a full-frontal shot of a naked man -- has received well over three million hits. While many comments have been supportive, others accused her of confusing freedom with "degradation and prostitution". A group of Islamic law graduates have launched a legal action against Elmahdy and her boyfriend, accusing the pair of "violating morals, inciting indecency and insulting Islam."

She hasn't had much support from liberals, either, many of whom fear that actions like hers play into the hands of Islamist social conservatives who favour the imposition of Saudi-style restrictions on women in the country. A spokesman for the April 6 Youth Movement denied reports that she a member by asserting that "We are conservative youths, and we always encourage our members to be role models as far as ethics are concerned . . . How can we have accepted the membership of a girl who behaves like this?"

"Where is the democracy and liberalism they preach to the world?" was Elmahdy's response to that remark. "They only feed what the public wants to hear for their political ambitions."

By exposing herself, Aliaa Elmahy may also have exposed the shortcomings of a political revolution that is certainly unfinished and may turn out to be stillborn. In the CNN interview she described sexism in Egypt as "unreal" and suggested that many women wore the veil "just to escape the harassment and be able to walk the streets." There's little evidence that events since January have improved that situation. The alliance of convenience between secular liberals and Islamists seen in both Egypt and Tunisia has temporarily masked deeper tensions about the nature of society. And it is on the bodies of women that these debates so often seem to play out.

Her gesture also poses a challenge to Western liberals. Her very existence as a young, sexually-active, atheist feminist questions widely-held assumptions about the fundamentally conservative nature of Islamic societies. Perhaps, for that very reason, she is likely to provoke more embarrassed shuffling of feet than open support. And some may consider her methods questionable, not merely because she thereby puts herself in danger.

For there's something curiously old-fashioned about Elmahy's action. It seems like a harking back to that brief moment (approximately between the Lady Chatterley and the Oz trials in the UK) when sexual liberation and nudity were part and parcel of revolutionary politics. We've moved on from that. Today, displays of naked (especially female) flesh no longer look politically radical. Instead they tend to be deplored on the Left as sexualising and objectifying, symptoms on the one hand of crass commercialism and, on the other, as merely the exploitation of vulnerable women for male delectation. It's a view that (for different reasons) our own religious conservatives are happy to endorse.