The first day of the court's new term, which is set in law as the first Monday in October, included denials of hundreds of appeals. Chief Justice John Roberts opened the new session in a crowded courtroom that included retired Justice Sandra Day O'Connor.

Last term, the justices handed down several opinions that limited state regulation of business in favor of federal power. Several justices posed skeptical questions in this term's first case, whether federal law prevents smokers from using consumer protection laws to go after tobacco companies for their marketing of "light" and "low tar" cigarettes.

The companies are facing dozens of such lawsuits across the country.

The federal cigarette labeling law bars states from regulating any aspect of cigarette advertising that involves smoking and health.

"How do you tell it's deceptive or not if you don't look at what the relationship is between smoking and health?," Chief Justice John Roberts said during oral arguments on the case.

Three Maine residents sued Altria Group Inc. and its Philip Morris USA Inc. subsidiary under the state's law against unfair marketing practices. The class-action claim represents all smokers of Marlboro Lights or Cambridge Lights cigarettes, both made by Philip Morris.

The lawsuit argues that the company knew for decades that smokers of light cigarettes compensate for the lower levels of tar and nicotine by taking longer puffs and compensating in other ways.

A federal district court threw out the lawsuit, but the 1st U.S. Circuit Court of Appeals said it could go forward.

The role of the Federal Trade Commission could be important in the outcome. The FTC is only now proposing to change rules that for years condoned the use of "light" and "low tar" in advertising the cigarettes, despite evidence that smokers were getting a product as dangerous as regular cigarettes.