What do colleges uses your social security number for besides identifying you?

Do they use it to identify you also for financial aid & do they do some type of education history or background check? My friend went to home school with me but she also did two regular years of high school & she didnt include info on the other high school she went to so now she is thinking she might get in trouble with the colleges she applied to for not including every school she went to? We graduated in 2010 & she thinks that since she provided her ssn they will be able to look up that info about her other school? She only sent in the homeschool info & that transcript, she didnt give them the other schools transcript because she had a some bad grades on it & she had good grades on the homeschool transcript so what else do college use the ssn info for can they check to see all of your education history also & can she get in big trouble like fined or jail time possibly? Technically she isnt lying or faking anything because she did got to homeschool with me all 4 yrs but she just wanted to try out the regular schooling for the 1st 2 yrs & she was still homeschooled those 1st 2yrs also