Bresnan Communications LLC

NebuAd Inc., a company that sought to target ads to consumers based on their online behavior, is going out of business after facing scrutiny over whether its technology infringed on the privacy of Internet surfers.

In court filings this week, NebuAd said it has been winding down its business since last year. It laid off virtually all its employees in July and August, closing its office in Redwood City, Calif., in September. NebuAd once employed over 60 people.

Angry online subscribers who had their Web surfing habits tracked in detail are suing a Silicon Valley startup that created the technology and six Internet service providers that briefly used it.

The 15 customers who filed the lawsuit in federal court here Monday demand more than $5 million in damages and are asking a judge to turn the case into a class action representing tens of thousands of Internet subscribers.