Need Help about paycheck deductions discrepancy

Hello! Everyone. Here is the issue.
It is no about me, but about my father.
My father has been working for years and he has been doing his taxes every year without delay. He is an undocumented worker, too. However, in the last two years, he got a new job, and he has been getting his paycheck normally with the right amount of money he deserves. Nevertheless, two month ago, he has been deducted money from his paycheck from the state tax California. 10% percent is been deducted from his paycheck.
However, he made a phone call to the IRS in order to find out, why is he being deducted money if he has made his taxes every miserable year. This is what the employee who works for the California Franchise Tax Board(The department that collects state personal income taxes and bank and corporation taxes for the State of California.
Access to forms and tax information) said to my father, "because you are using somebody's ssn you are being deducted." But here is my question, Why is he beeing deducted money if he has been doing his taxes? IS there any law that gives the right to the irs to deduct money from undomcumented workers in california or all over usa? What are the possible consequences that can cause this problem? i am also worry about my father's future in this country. What if he is be criminalize or deport? Is this kind of situation happening now to others Undocumented workers? For what reason are they doing this.
I know that the state of califonia is in a economic crisis that affects of all us, but does not meanthey have to steal money from people who break their bones to brings food to their table.
I want to know your history or somebody history about this issues. I want to know the reasons. I forget something else. The man works for the irs told him to renounce to his job, but why the hell is my father going to do that. I am very concerned and please help me. What can one do renounce to the job or keep going?

Well, our wonderful governor and state legislature decided it would be super cool to take more money from people that work. Its 10% more to be exact. So maybe that explains the extra money being deducted?

http://articles.latimes.com/2009/oct...fi-state-tax31


and for the record, i am not complaining. I feel extremely blessed to have a job and I thank God that I do have one. But that might be the answer you were looking for.

Well another reason, aside from the tax increase, is because since your dad has been using someone else's security number, the other person has prob not been doing his taxes or owes money or many different things, so your dad is basically paying for that money. I knew a friend that was using someone else social and the other person had not been doing his/her taxes so they started deducting money from my friends paycheck. After a while they went into her checking and savings account, since she used the same social to open an account. In the long run she basically paid more than 2000 dollars just on taxes. So it could be that, your dad would have to basically change his social and report the new one to the company, or see how much is due in back taxes on that social.