Last year was the first time same-sex couples could check husband or wife on the census form. In fact, it was the first time gay marriage was legal anywhere in the US come census time, since Massachusetts became the first state to legalize it in 2004. Yet, not all of the 130,000 couples who identified as spouses are legally married or in legal domestic partnerships. The Census Bureau estimates that number to be around 100,000. So about 30,000 couples made a silent protest by marking themselves down as married, when they likely don't have the right to be.
Overall, however, experts believe the stats on gay couples are unrepresentative of reality. The census found there's a total of 646,464 gay couples in America, but that figure could be 15 percent lower than the actual number, since stigmatization or fear of discrimination might dissuade couples from reporting their sexuality to the government. Considering the US government just stopped officially discriminating against openly gay Americans in the military with don't ask, don't tell, I don't blame them. Even so, the fact that the number of reported same-sex couples increased by 80 percent from 2000, reflects progress made over the last decade.