By Lisa Wangsness, Globe Staff  |  June 12, 2006

A controversial campaign to identify supporters of a constitutional ban of gay marriage in Massachusetts plans to launch a similar website in Florida today.

KnowThyNeighbor.org, a website that contains a searchable database of the names of Massachusetts residents who have signed a petition for a constitutional amendment to outlaw gay marriage, has helped a church in Jacksonville, Fla., build a similar database of Floridians who have signed a ``marriage protection" ballot initiative in their state. The Florida names will be available on KnowThyNeighbor.org or through a link on the church's website, christchurchofpeace.org .

The website's creators say its purpose is twofold -- to root out signature fraud and to provide public information that gay marriage supporters can use to identify petition signers they know and engage them in ``open and meaningful dialogue." But opponents of the site say its real purpose is to intimidate.

Kris Mineau , the president of The Massachusetts Family Institute , a sponsor of the amendment banning gay marriage, said Massachusetts' latest export was meant to scare Floridians away from the petition.

``If what you say is true, obviously their intent is to intimidate voters in Florida, as well as Massachusetts," he said.

But Rob Henry , cochair of the Freedom to Marry Coalition of Massachusetts, said yesterday the site can provoke constructive debate as long as it provokes ``friendly, nonconfrontational" discussion.

That is precisely how it is meant to be used, said Tom Lang , an antiques dealer from Manchester-by-the-Sea who cofounded KnowThyNeighbor.org.

``We need to do this nationwide," Lang said. ``The way we're using it is having conversations with people we know, and that to me is a very important thing."

KnowThyNeighbor.org's expansion underscores how, two years after it became the first state in the country to legalize gay marriage, Massachusetts continues to be the epicenter of the issue. Last week, the US Senate defeated a constitutional amendment to ban gay marriage pushed by President Bush. Bush invoked the Massachusetts Supreme Judicial Court in arguing for protecting what he called the ``most fundamental institution of civilization." Thirteen states had constitutional amendment questions pending as of last month, according to the website of the Human Rights Campaign, a national gay rights advocacy group.

The proposed Florida amendment defines marriage as ``the legal union of one man and one woman" and prohibits the recognition of any other union that would be its ``substantial equivalent." Proponents had hoped to put it on the ballot this November, but they gathered only about 466,000 of the 611,000 signatures required, according to John Stemberger , state chairman of Florida4Marriage.org , the coalition leading the drive. Because the signatures are valid for four years, however, he said they are almost certain to reach their goal by 2008.

Michael Schumpert , a cofounder of the Christ Church of Peace , said he e-mailed Lang after reading about his website in The Advocate , a national gay and lesbian magazine. He wanted to see if his church could build a similar site for the Florida petition. In April, the church board voted unanimously in favor of the idea, and volunteers began gathering signatures of those who had signed the antigay marriage petition from each county across Florida.

KnowThyNeighbor.org helped the church create a database of roughly 300,000 signatures . The church is still trying to get the rest of the names in digital format, Schumpert said. Lang said the site is prepared to handle several million visitors; the Massachusetts site had more than 2 million in its first 36 hours of operation .

The Rev. Gary DeBusk , pastor of Christ Church of Peace, said his congregation wanted to add a pro-gay, Christian voice to the debate, whose loudest opponents are more conservative Christian churches. While he said he wants people to use the site to have discussions with signers, he said those conversations are critical.

``We're trying to say you cannot just take away people's rights without being held accountable for that," he said.

The effect KnowThyNeighbor.org has had in Massachusetts remains unclear. Mineau points out that amendment proponents gathered a record 170,000 signatures . But Lang said the site helped uncover numerous fraud claims, and that gay and straight people have praised the site for helping people ``stand up for their rights."

KnowThyNeighbor.org's success depends upon a degree of peer pressure. And Stemberger said the Web site might backfire in Florida.

When he publicly complained that a police officer recently tried to prevent him from collecting signatures at a Promise Keepers rally, he said the media coverage provoked an outrage.

``We got hundreds of letters and e-mails from people saying, `Fight the fight,"' he said. ``It really energized people."

But he added that most Floridians probably wouldn't even be aware of the site ``unless they do massive TV ads or begin to really harass people in specific ways."

Lisa Wangsness can be reached at lwangsness@globe.com.