Many in the gay and lesbian community hoped to celebrate the victory of Barack Obama, but instead of partying they have taken to the streets in fury after California voted to reverse gay marriage.

The vote in favour of Proposition 8 prompted a gay rights demonstrations in Los Angeles last night.

Activist and writer Bill Browning uses the word 'angry' 17 times in a single blog post to describe his feelings. "I'm angry with Americans for transcending race, but not sexual orientation," he writes.

The vote means that 18,000 same-sex couples who have married in California since June, including a number of celebrities, could have their marriages annulled.

Eatingoutloud.com blogger Allen switched his wedding ring to his middle finger and held it up as a photo jesture to the people of California. He urges others to do the same.

I awoke this morning to learn that my relationship with my partner is no longer valid. It's no longer legal. It's somehow sub-par, not equivalent, not worthy of protection. And you know what? I'm pissed and tired of holding it in. I welcome supporters of gay rights to snap your own photo showing your wedding ring on your middle finger.

Legal challenges have already been mounted, notably by Robin Tyler and Diane Olson, the first same-sex couple to get married since the gay marriage was allowed in the state.

"It's never happened in American history where a group of people have been in a constitution and then taken out again," Tyler told CTV.

But who to be angry with? Allen targets the Mormons. And Bill is cross with African-American voters who backed Prop 8 by 69% to 31%.

But Dr Anonymous, "a queer person of color" explains why black people should not be blamed.

Meanwhile, Google has caught up in the row for allowing anti-gay marriage adverts to appear on websites against their owners' wishes.

Google's stance prompted a furious post by Peter Kirn, editor of one such site - Create Digital Music.

He wrote:

Google failed to deliver the solution it promises its publishers. They violated their own policies, violated the principle of their service, violated the trust of their publishers, and then failed to respond to an issue that was deeply time-sensitive.

Michael Arrington on TechCrunch wrote: "We'll look back on measures like Prop 8 as little different than attempts to stop women's suffrage or the civil rights movement of the 50s and 60s."

And then he realised that TechCrunch itself had carried ad links to protectmarriage.com.