SAN FRANCISCO (Reuters) - The rejection of gay marriage by California voters has unleashed a hurricane of protest on the Internet, with some supporters venting their anger and others planning national demonstrations.

Amy Balliett, 26, used her lunch break last Friday to start a website -- www.jointheimpact.com -- to call for coordinated action across the United States this weekend.

In a few days, more than 1 million people have visited her site and dozens of marches and meetings are now planned for 1:30 p.m. EST (1830 GMT) on Saturday.

By the evening jointheimpact.com was created, it was visited 10,000 times. By Sunday, there were 50,000 visits per hour and the computer running the site crashed. It has moved computers twice since in an effort to keep up.

“Why do we have to wait for someone to step up and say let’s do a protest?” Balliett remembered thinking after her friend, Willow Witte, posted a blog about California. “Over email we decided to do it.”

California’s Supreme Court opened the way to gay marriage in May, putting it among a handful of states, provinces and European countries that allow same-sex couples to marry.

But after a $70 million-plus campaign, a measure to ban gay marriage in California passed in a vote held alongside the U.S. presidential and congressional elections on November 4, stunning a community that had expected its first major ballot box win.

Balliett’s plan is to create an educational dialogue but others have diverse goals or are simply speaking out as Facebook, MySpace, Twitter, text messages, blogs and websites buzz with protest about the vote in California.

Members of the gay, lesbian, bisexual and transgender community say they were hurt deeply and want to bring their civil rights argument -- that same-sex couples deserve the same treatment as others -- to a national audience.

“It took the rights being taken away from people to really get across that it’s not a California issue. It’s a nationwide issue,” said Brandon Williamson, who was about to start his own protest website when he found Balliett’s and joined forces as publicist.

‘IT’S MASSIVE’

Gay marriage is legal in two U.S. states, Massachusetts and Connecticut, where court-approved same-sex weddings began on Wednesday. But dozens of states have laws that limit marriage to a man and a woman.

This month’s election also saw bans on gay marriage pass in Florida and Arizona, while Arkansas stopped gay couples from adopting children.

This is not the first time gay marriage proponents or their adversaries have used technology. Both sides of California’s Proposition 8, the gay marriage ban, used websites and more.

But the ability of the Internet to organize grass-roots movements has been especially clear since the ban’s passage.

Balliett, whose job is publicizing websites through searches, says she has never seen anything like it. Civil rights campaigners agree.

“It’s massive,” said Scott Robbe, a gay rights veteran based in Wisconsin, adding that election campaigns from Howard Dean to Barack Obama had paved the way for the civil rights movement to use the Internet on a massive scale.

Balliett directs volunteer organizers to start MySpace and Facebook sites for their own cities but the Internet action is about more than her efforts.

The Facebook group “1,000,000 Million Strong Against Newly Passed Prop 8” has about 68,000 members, for instance. The group’s creators identify themselves as high school students.