On Aug. 13, ExxonMobil pleaded guilty in federal court to killing 85 birds that had come into contact with crude oil or other pollutants in uncovered tanks or waste-water facilities on its properties. The birds were protected by the Migratory Bird Treaty Act, which dates back to 1918. The company agreed to pay $600,000 in fines and fees.

ExxonMobil is hardly alone in running afoul of this law. Over the past two decades, federal officials have brought hundreds of similar cases against energy companies. In July, for example, the Oregon-based electric utility PacifiCorp paid $1.4 million in fines and restitution for killing 232 eagles in Wyoming over the past two years. The birds were electrocuted by poorly-designed power lines.

A July 2008 study of the wind farm at Altamont Pass, Calif., estimated that its turbines kill an average of 80 golden eagles per year. The study, funded by the Alameda County Community Development Agency, also estimated that about 10,000 birds—nearly all protected by the migratory bird act—are being whacked every year at Altamont.

Altamont's turbines, located about 30 miles east of Oakland, Calif., kill more than 100 times as many birds as Exxon's tanks, and they do so every year. But the Altamont Pass wind farm does not face the same threat of prosecution, even though the bird kills at Altamont have been repeatedly documented by biologists since the mid-1990s.

The New York Times [no link], for all its problems, can still do good reporting, one example being its coverage of unions using environmental regulations in California to try to pressure developers into signing "agreements pledging to use union labor."

"If they refuse," reports Todd Woody, "they say they can count on union groups to demand costly environmental

The difference in unions using greenmail and blackmail, says Sherk, is that in greenmail "unions use government bureaucrats instead of armed thugs to intimidate businesses." And "it happens repeatedly."

Companies that are victims of greenmail should stand up to union shakedowns. While refusing to unionize won't allow companies to avoid the snarl of environmental rules, it will improve their chances to operate their businesses at lower costs and provide investors with better returns.