"It's just amazing to see some women doing real protest, making a real noise," says Hayley Foster Da Silva, 29, a pharmacist and activist holding a sparkly home-made sign that reads "Free Pussy Riot". "It's all about freedom of speech."
Six months after the Russian feminist punk outfit Pussy Riot broke into an Orthodox church and played a three-minute anti-government rock track, three members of the band sit in a Moscow court, awaiting the verdict of what many outside Russia have called a "show trial" for "hooliganism".
As Nadezhda Tolokonnikova, Maria Alekhina and Yekaterina Samutsevich are sentenced to two years' jail, across the world, protests have been called in support of the band. In the Ukraine, a member of the women's protest group Femen was filmed sawing down an enormous crucifix, while in New York and London, crowds of angry men and women in miniskirts and neon balaclavas gathered outside embassies. If Putin's government wanted to avoid embarrassment by prosecuting these young women, it hasn't worked.
Outside the Russian embassy in London, 200 people are crammed into a small police pen on the pavement. Many of them wear Pussy Riot's signature outfit of pretty dresses and balaclavas, including the men. There are a handful of the usual left-wing protest faces in evidence, among them the ubiquitous young party member flogging copies of Socialist Worker, but there's a large number of artists and musicians here to support freedom of speech and creativity.
"There's a great punk rock tradition of feminist artists using their bodies in explicit ways to make political points," says Kira O'Reilly, a performance artist wearing glasses over her bright pink balaclava. "Pussy riot are working within that tradition in a very clever way. It's horrific what has happened to them."
Alongside the artists, the feminists and the mothers and babies wearing bright sliced-up tights over their heads, many Russians have joined the protest.
"The authorities have really shot themselves in the foot, and given the girls world exposure that they probably would not have earned otherwise," said Yana Melkumova, 30, a fashion worker from Moscow. "I was unaware of their existence until the trial. But when I speak to my mother on the phone she seems unaware of the protest and of the change of mood in Russia. I don't know how real that change of mood is."
"I'm a political émigré, I left Russia last August because I was an organiser of anti-Putin protests," says Evgeny Leg-idin, 42, who wears a balaclava and an anti-Putin T-shirt.
"Pussy Riot show us that you shouldn't be afraid to speak freely about corruption in the clergy, in the government. People are afraid but artists are supporting all over the world. There is no democracy at all – Russia has become a dictatorship again, and Putin is the Tsar."
Three men wearing Guy Fawkes masks, the motif of the online anti-censorship protest group Anonymous, arrive an hour late and begin blasting out Pussy Riot's songs from a portable speaker.
The crowd becomes noisier and bolder, chanting at passers-by: "I say Pussy! You say Riot!" They hold signs demanding the release of the band, not facing the embassy but instead facing the street an d the waiting cameras. Nobody expects the Russian authorities to listen, this is all about creating a media spectacle. One suspects Pussy Riot would approve.