Emma Watson has been threatened by internet trolls on the same site which has hosted naked celebrity photos, just days after she addressed the United Nations on gender equality.
A web page entitled “Emma You Are Next”, featuring an image of the Harry Potter star next to a countdown, appeared to have been created by a user of image-sharing website 4chan.
Private images of Jennifer Lawrence and model Kate Upton were posted on the site last month.
And US media reported that Rihanna and Kim Kardashian were targeted by the hackers at the weekend.
Watson, a Goodwill Ambassador for UN Women, launched the HeForShe campaign in a speech at the world body in which she appealed to men to speak out for equality.
The 4chan web page, which also carries the words “never forget, the biggest to come thus far”, sparked debate on social networking sites including Twitter and Tumblr and the timer was set to end at midnight on Friday.
After the first set of hacked images were posted on the internet at the beginning of September, Watson said on Twitter: “Even worse than seeing women’s privacy violated on social media is reading the accompanying comments that show such a lack of empathy.”
And in her UN speech Watson , 24, said she wanted to challenge gender stereotypes after she felt she had been “sexualised” in the media at just 14.
She said: “For the record feminism by definition is the belief that men and women should have equal rights and opportunities. It’s the theory of the political, economic and social equality of the sexes.
“I started questioning gender-based assumptions a long time ago. When I was eight I was confused about being called bossy because I wanted to direct plays we put on for our parents but the boys were not.
“When I was 14 I started to be sexualised by certain elements of the media.
“When I was 15 my girl friends started dropping out of their beloved sports teams because they did not want to appear ‘muscly’.”
Watson added she had been “privileged” when growing up as her parents and teachers had been “inadvertent feminists”.