They see it if you put it down. From what A Berkeley rep told me- that information is completely optional. She advised me to not put down my family's income....if you feel that it would hurt your chances of potentially getting scholarships, don't put it down!
@larinaga- why wouldn't it make sense? They are blind to race and gender, so it wouldn't make sense for them to be able to view our names which would most likely reveal our gender and possibly our race too. I believe they just see a number.