These are the steps in marriage related GC-sponsorship: USC marries Alien (resident in USA on a non-immigrant visa, like H1b or L-1 OR an alien living in India or some other non-US country) USC sponsors Alien for adjustment or status within USA or immigration from India or some non-US country. After a long wait, the spouse of USCitizen gains a "conditional" immigrant status. The "conditional" aspect is like a "probationary" job; adequate execution on the job results in tenure. Tenure on that job requires the USCitizen to apply to remove those "conditions", after the probationary period (2 years) is over. "Honeymoon photos" as evidence of the bona fides of the marriage has been mentioned in one of the posts here. Only after living with the USC for 3 years after acquiring the Green Card, the new immigrant spouse may apply for US citizenship. This would take a year or more to achieve. And after that the new US citizen can sponsor his relatives to come to the USA, which might take a few years. Nothing in this scheme is quick and easy. Years of wait involved in each step. Thus, we already have sufficient safeguards to protect "the friend" from fraud marriage. Naturally the USCitizen has to exercise caution during the probationary period of the GC-marriage. The US citizen has to engage in "safe" behavior so that his/her offer of tenure to the marriage is not under duress when the probation ends. Early children in a marriage cause duress for further negotiations of tenure irrespective of whether or not a GC is involved in the case.