A terrible piece of news from Libya:

The Libyan human rights activist Salwa Bugaighis has been shot dead by unknown assailants at her home in Benghazi on the day of the country’s general election.

“Unknown hooded men wearing military uniforms attacked Mrs Bugaighis in her home and opened fire on her,” said a security official, who did not wish to be named.

Her husband is missing.

Bugaighis, a lawyer, played an active part in Libya’s 2011 revolution, which overthrew the regime of Muammar Gaddafi. A former member of the National Transitional Council, the rebellion’s political wing, she was vice-president of a preparatory committee for national dialogue in Libya.

The US ambassador to Libya, Deborah Jones called the news “heartbreaking”, and on her Twitter account denounced “a cowardly, despicable, shameful act against a courageous woman and true Libyan patriot”.

Earlier on Wednesday Bugaighis had participated in Libya’s general election. She published photos of herself at a polling station on her Facebook page.

Maybe the Festival of Dangerous Ideas should offer a talk on why that was morally justified.