The rich pay taxes period, and yes they can get substanial deductions depending on how they spent or earned that money. But to have that article state they paid zero tax is absurd. We all pay taxes every day and so do they when the buy fuel, clothing, payroll deductions, etc.
I do admit that the current IRS thing is hokie and I'm in favor of a National Sales Tax to eliminate the IRS, this way everyone pays their fair share (yes even the people who are in the country illegally).
The US has 3.1 millionaires, to say 7,000 paid zero taxes, means that 99.75% paid taxes according to that web sites math. I'd take 99.75% all of the time. Again the current IRS tax system stinks and it is not fair.