According to OUT-LAW, all 500 of the world's biggest companies have been affected by typosquatters, who register Domains which are very similar to the companies' trademarks in order to profit from misdirected traffic.

Many of these domains infringe trademark laws, but catching and prosecuting typosquatters is a difficult business. "If you had a typosquatter operating a website via a Domain Name that was one or two letters different to the trade mark owner's site and was obtaining advertising revenue that way on the back of that domain, then you could argue that they were using the brand in the course of trade. They'd then have a reasonable case of trademark infringement and passing off," said Lee Curtis, a representative of OUT-LAW.

Because it is so inexpensive to register a domain name, many domainers hold thousands of domains and earn millions of dollars a year through pay-per-click advertising. A representative of pharmaceutical company Pfizer argues that typosquatting dilutes brand recognition and costs millions or even billions of dollars to brand owners.