One way an immigrant can quickly obtain a green card is to marry a U.S. citizen. So naturally a lot of green card marriage fraud occurs annually, say some people. You've likely heard of "mail-order brides." Well, now there are loads of websites that help people in other countries hook up with Americans willing to marry them for money just so the foreigners can enter the U.S. legally.
It's true such websites exist. And it's true that marriage fraud occurs. But not as much as you might think. Between 2007 and 2009, U.S. Citizenship and Immigration Services discovered about 600 fraudulent green card applications, but that was among 700,000 petitions for foreign spouses, which is only about .0009 percent [source: Dwyer].
Marriage fraud does occur partly because U.S. immigration laws make it relatively easy for the spouses and minor children of citizens to quickly enter the country, in order to reunite families. In 2013, 66 percent of the total number of new LPRs — lawful permanent residents, or green card recipients — were family-sponsored immigrants. Foreign spouses made up about 38 percent of all family-sponsored LPRs [source: Monger and Yankay].