In what could be a significant ruling for the online ad industry, a US judge has found in favour of technology that allows pop-up ads to appear over other companies’ websites.

Judge Gerald Bruce Lee of the US District Court in Alexandria, Virginia, ruled that the use of such software does not infringe the trademark and copyright of the sites over whose content ads appear.

The decision could lead to more bellicose online ad campaigns. For example, consumers buying from one website could be faced with pop-ups from a rival offering a lower price.

The technology at the centre of the ruling is distributed by companies such as Gator and, which offer consumers free software such as screensavers and video players. These come bundled with programs that track a consumer’s web habits and send them ads accordingly. Companies that advertise via Gator and WhenU therefore have the chance to offer a better deal to surfers on a competitor’s site.

Unsurprisingly, this has not gone down too well with website operators and online publishers. Over a dozen lawsuits have been launched against Gator and WhenU in the past two years, on the grounds that the pop-ups violate the trademarks and copyrights of the site being visited.

Judge Lee’s decision came in a suit against WhenU filed by truck rental giant U-Haul International. He ruled that the ad firm’s software did not “copy or use U-Haul's trademark or copyright material.”

The judge concluded that computer users had “invited” the pop-ups by installing the free programs. “Ultimately, it is the computer user who controls how windows are displayed on the computer desktop.”

Lee also rejected claims that the pop-ups deface the original website’s content. “The Windows environment permits a user to open multiple applications and windows at the same time, with the different windows overlapping one another. WhenU's ad is merely another window on the user’s computer desktop.”

U-Haul is considering whether to appeal. The outcome of the case could have a bearing on similar suits filed in different courts.

“The question is whether you can have a technology that puts an alternative in front of the consumer,” declared WhenU ceo Avi Naider. “The answer is a resounding yes.”

However, Naider may yet find the answer from ad-weary surfers is “no”. Internet service providers are beginning to offer subscribers software that will either block pop-ups or get rid of the tracking programs on which Gator and WhenU rely.

Data sourced from: The Wall Street Journal Online; additional content by WARC staff