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

This means that advertisers could do things like automatically create scores of ad campaigns and test different ads on LinkedIn, or quickly change spending across LinkedIn and other social media outlets in real-time, LinkedIn says.

FORBES: LinkedIn Targets Ad Growth With New Ads API

This page's creator is also an amateur horror film producer, and it shows in the site's layout, including clever artwork and mood music that automatically downloads and plays ad nauseum as long as you are on a page.

CNN: Halloween spirits are on The Web