At a Blockbuster store on Lee Highway in Fairfax County, Nisha Kumar yesterday grumbled at the suggestion of yet another Big Brother: the sale by video companies of information about the rental habits of their customers. "What if you get a lot of gory horror flicks?" Kumar asked. "Is that anybody's business?"

It's not, say many video customers.

The question of whether video rental habits ought to be sold to the highest bidder joined the debate this week over privacy issues as Blockbuster Entertainment Corp., the nation's largest video rental company, denied a published report that it will sell rental profiles.

With 34 outlets in the Washington area and about 1,500 around the country, Blockbuster is compiling a computerized database that tracks movie selections by its millions of members. That information is valuable, company officials said, and many direct marketing firms have sought to rent or buy it.

Last week, the Wall Street Journal quoted Blockbuster vice president Allan Caplan, who is overseeing the database project, as saying the video firm would release information about the categories of movies its individual customers rent -- but not the actual titles.

A spokesman for the Florida-based video giant yesterday denied that the company will sell or rent the data. However, Wally Knief, a spokesman for Blockbuster, refused to term the article inaccurate, but said that Caplan "was not speaking for Blockbuster." "{W}e are not, have not and will not sell or rent membership lists," Knief said.

Caplan was not available for comment.

Knief said his firm plans to use its data "for internal purposes only." These include ambitious marketing ventures such as offering club members reduced-rate tickets for Blockbuster's cruise ships and for events at amphitheaters to be built around the country.

Civil libertarians and marketing association officials yesterday said they believed the sale of renter profiles would be bad for both the public and the video industry.

Janlori Goldman, director of the American Civil Liberties Union's Project on Privacy and Technology, said releasing the categories of movies that a video club member checks out -- such as westerns or horror films -- is legal only if people applying for membership are given a chance to reject release of such data.

Knief said he had "not heard any discussion" about including such an option on the application for Blockbuster membership.

Officials of West Coast Video and Erol's Inc., the nation's second and third largest video companies, said they refuse to provide data about renters' preferences to other firms. Erol's, whose 112 outlets in Washington, Maryland and Virginia make it the largest movie rental chain in this region, will soon be taken over by Blockbuster in a $40 million deal announced in November.

Vast amounts of data about Americans' addresses, salary ranges and spending habits are already available to direct marketing firms and the general public from such diverse sources as credit agencies and motor vehicle offices.

It is used in targeted marketing -- identifying those people most likely to want to buy or use a product, and contacting them by mail or telephone.

Richard Barton, senior vice president of the Direct Marketing Association, said that "well over $200 billion" in sales were made this year through such marketing. The business "outstrips television, magazines and newspapers" for advertising revenue, Barton said.

Tens of thousands of U.S. companies, such as magazines and specialty catalogues, sell customer data to direct marketing firms. But the video rental business is generally considered to be the best source of identifying consumer interest in specific products and services, industry representatives said.

In 1988, Congress enacted restrictions on revealing video rental information after a reporter found that former Judge Robert Bork, a Supreme Court nominee, apparently had checked out James Bond and Alfred Hitchcock films.

Goldman, who worked on the so-called Bork Bill, said civil libertarians had tried to broaden the measure to include book clubs, frequent-shopper operations and many other retail firms, without success.

"Blockbuster is a small piece" of the picture of personal data being disseminated by companies, she said. Many firms are "looking for a second profit" from the information they compile for their own uses.

Goldman said many people are not aware that "lifetime profiles" of their purchasing habits can be developed through modern technology and sold to numerous companies. John Baker, senior vice president of the Atlanta-based Equifax credit marketing firm, said his is one of several firms selling basic information about 80 million U.S. households, or about 200 million people.

The practice of selling video rental lists, Blockbuster customer Steve Hamberg of the District said yesterday, would be "an invasion of my privacy. I don't think they'll do it, though."

"They already have so much access to personal information. I think it stinks," said Juliet Perry.

However, some customers were less concerned.

"Anybody can get anything they want from your credit record," said Ann Willey, who was at a Fairfax store. "I'm used to companies selling or renting my name. I just put their mailing in the trash if I don't want it."

Staff writers DeNeen L. Brown and Christine Spolar contributed to this article.