Domain names.

The advent of the domain name system has led to attempts by trademark holders to enforce their rights over domain names that are similar or identical to their existing trademarks, particularly by seeking control over the domain names at issue. As with dilution protection, enforcing trademark rights over domain name owners involves protecting a trademark outside the obvious context of its consumer market, because domain names are global and not limited by goods or service.

This conflict is easily resolved when the domain name owner actually uses the domain to compete with the trademark owner. Cybersquatting, however, does not involve competition. Instead, an unlicensed user registers a domain name identical to a trademark and offers to sell the domain to the trademark owner. Typosquatters—those registering common misspellings of trademarks as domain names—have also been targeted successfully in trademark infringement suits. "Gripe sites", on the other hand, tend to be protected as free speech, and are therefore more difficult to attack as trademark infringement.

This clash of the new technology with pre-existing trademark rights resulted in several high-profile decisions as the courts of many countries tried to coherently address the issue (and not always successfully) within the framework of existing trademark law. As the website itself was not the product being purchased, there was no actual consumer confusion, and so initial interest confusion was a concept applied instead. Initial interest confusion refers to customer confusion that creates an initial interest in a competitor's "product" (in the online context, another party's website). Even though initial interest confusion is dispelled by the time any actual sales occur, it allows a trademark infringer to capitalize on the goodwill associated with the original mark.

Several cases have wrestled with the concept of initial interest confusion. In Brookfield Communications, Incorporated v West Coast Entertainment Corporation the court found initial interest confusion could occur when a competitor's trademarked terms were used in the HTML metatags of a website, resulting in that site appearing in the search results when a user searches on the trademarked term. In Playboy Netscape, the court found initial interest confusion when users typed in Playboy's trademarks into a search engine, resulting in the display of search results alongside unlabeled banner ads, triggered by keywords that included Playboy's marks, that would take users to Playboy's competitors. Though users might ultimately realize upon clicking on the banner ads that they were not Playboy-affiliated, the court found that the competitor advertisers could have gained customers by appropriating Playboy's goodwill since users may be perfectly happy to browse the competitor's site instead of returning to the search results to find the Playboy sites.

In Lamparello v Falwell, however, the court clarified that a finding of initial interest confusion is contingent on financial profit from said confusion, such that, if a domain name confusingly similar to a registered trademark is used for a non-trademark related website, the site owner will not be found to have infringed where they do not seek to capitalize on the mark's goodwill for their own commercial enterprises.