Exxon Mobil Corp. (NYSE: XOM)'s record-setting quarterly profits last week prompted renewed calls for a windfall profits tax against the oil industry. The problem I have with these theory is that people usually do not explain what they mean by a "windfall."

"How does it differ from your everyday, run of the mill profit?" The Wall Street Journal noted in an editorial today. "Is it some absolute number, a matter of return on equity or sales -- or does it merely depend on who earns it?"

Also, is the government going to figure out how much Exxon deserved to earn and what gives the government the right to single out the oil companies for such treatment. Why not subject Google Inc. (NASDAQ: GOOG) or Warren Buffett's Berskshire Hathawy Inc. (NYSE: BRK.A) to a windfall profits tax too? They make lots of money, right?

Well, the reason why we don't penalize companies just because they make a lot of money is because that would be insane. As the Journal notes, it's hard to make the case that Exxon's profitability is excessive. In 2007, its profit margins were 10%, in-line with the industry average. The oil company's margins were worse than firms in the chemicals industry, pharmaceuticals, beverages and tobacco, the paper said.

Exxon Mobil is a pretty easy company to dislike. Its politics are reactionary, particularly on global warming. Its attitude toward alternative energy is skeptical. Wall Street already gave a thumbs down to its latest earnings report which is a far more effective punishment than a windfall profits tax.

Putting the squeeze on the oil industry may feel good, but it won't bring back $2 gas prices. Those days are gone forever.

Venezuela has started collecting its new foreign oil companies windfall profits tax, as part of President Hugo Chavez' plan to gain a larger share of oil company profits, The Associated Press reported.

The tax is based on the monthly average price of benchmark Brent crude oil. The tax kicks in when the price of benchmark Brent crude sits above $70 per barrel, The Wall Street Journal(subscription required) reported. If oil prices remain above that threshold for one month, the state will take 50% of the difference between this average and the final sale price of every barrel. When Brent crude exceeds the $100-a-barrel average, the rate will rises to 60%.

'21st-century socialism'

President Chavez, a Socialist, has said the tax is necessary to fund key social programs as part of his effort to implement an economic and social system he calls "21st-century socialism." Critics say the tax will slow investment and development in the oil sector, and also discourage other foreign direct investment in Venezuela.