Each year, hundreds of thousands of marriage-based green cards are issued in the United States. Some are no doubt fraudulent -- that is, entered into not for love or for purposes of embarking on a shared life, but for the sole purpose of getting the immigrant a green card (U.S. lawful permanent residence).
U.S. Citizenship and Immigration Services (USCIS) often says that between one fifth and one third of marriages between U.S. citizens and immigrants are fraudulent, although it's impossible to say for sure. Many people know someone -- or know someone who knows someone -- who got married in order to get a green card. Even immigration lawyers get fooled sometimes, when they acompany their clients to a green card interview and USCIS uncovers a fraud.
There are legitimate national security issues where marriage fraud is concerned. If someone can gain entry to the U.S. simply by paying a U.S. citizen for the privilege, this may open the door to people who intend to commit crimes or acts of terrorism in the United States.
However, it should be noted that U.S. laws erect several barriers against people who intend to commit marriage fraud. Contrary to popular myth, marriage to a U.S. citizen does not make the immigrant a U.S. citizen. The immigrant is first -- after having presented documentary proof that the marriage is the real thing, as well as passing an interview with an immigration offiial -- given conditional residence, which expires after two years. In order to convert from conditional to permanent residence, the immigrant must once again, with the help of the U.S. citizen spouse, prove the validity of the marriage. The immigrant's case can be reviewed a third time upon applying for U.S. citizenship, at which time their likely divorce may raise questions -- and lead to deportation proceedings.
What's more, marriage to a U.S. citizen does not help a person get around the various grounds of inadmissibility found within the immigration laws. A person with a history of crimes, security violations, or terrorist acts is not likely to be given U.S. residency -- or can have that residency later taken away.
If the immigrant marries a lawful permanent resident, the path to a green card is even more difficult -- it usually involves waiting outside the United States for around five years for an immigrant visa to become available.
Beyond the built-in barriers to marriage fraud found within the application process, the immigration authorities take steps to investigate potential frauds. For example, Chris Rhatigan, USCIS spokesperson, told ABC News in 2010 that the immigration authorities will "go to the address they give us to see that they actually live there." (See the article, "Immigrant Couples Face Scrutiny in Bid to Root Out Sham Marriages.") More than 600 fraudulent marriage-based green card cases were uncovered between 2007 and 2009, according to the ABC report.
Although some cases of fraudulent marriage can easily be defined as criminal acts -- particularly when money is exchanged or it's part of an organized conspiracy of arranging marriages -- in other cases they're harder to condemn.
For example, how does one regard the case of a couple who have been dating, and wouldn't ordinarily be ready for marriage, but see that it's the only way for them to stay together long enough to find out whether they'd like to stay together forever? Or the case of a gay or lesbian couple where the U.S. citizen half had, until the Supreme Court removed the barriers created by federal law ("DOMA") in 2013, no ability to petition for the partner or spouse to immigrate, but meanwhile a good friend of theirs, of the opposite sex, would happily marry the immigrant in order to help out?
Strictly speaking, such cases constitute marriage fraud. But they are important to keep in mind when viewing any statistics in this area.