This information gets sent automatically to every ad company with a presence on a Web page unless the website owner takes steps to prevent it.

WSJ: They Know What You're Shopping For

In a web-based attack scenario, an attacker would have to host a website that contains a specially crafted web page that is used to exploit this vulnerability.

FORBES: Connect

Because search results can be so important to website traffic, considerable effort is spent trying to manipulate search engine results, artificially moving a web page up the rankings.

BBC: NEWS | Technology | Open source search effort starts