Call the IRS and I'm sure they'll give you the definition of "income".
FICA (Social Security) is a scam. The politicians (particularly those on the left) use it shamefully as a way to buy votes. At least reform the system: http://www.socialsecurity.org/
Most sales taxes are imposed on a state and local level, but there's a move to impose more of them on the federal level. I don't see where it matters - the sales taxes you pay are a direct percentage of what you consume.
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