The Wall Street Journal probe discovered that spying on Internet users is one of the fastest-growing businesses on the World Wide Web.

《华尔街日报》的调查发现，目前，监视互联网用户已经成为万维网上成长最快的生意之一。

Today, tracking consumers is far more intrusive than the public realizes. For example, the top 50 websites in the US on average installed 64 pieces of tracking technology onto the computers of visitors, usually with no warning.

现如今，追踪技术的植入程度已经远超社会大众的想象。例如，全美最大的50家网站平均在访问者的电脑上安装了64种追踪技术，而且通常都没有任何警告。

The "cookie"- a tiny text file put on your PC by websites or marketing firms which might be used to remember your preferences for one site, or to track you across many sites-is already old news. There are new and more complex tools such as "beacons" which scan in real time what people are doing on a webpage. These beacons instantly assess the Internet user`s location, income, shopping interests and even medical conditions.

过去，网站或营销公司会在你的电脑上安装一个小文本（cookie），用来记录你对一个网站的喜好，或者跟踪你访问各个网站的情况。但如今，像beacon这种更新颖、更复杂的软件可以在人们浏览网页时进行实时扫描，然后立即对用户的地址、收入、购物兴趣，甚至医疗条件等因素进行评估。

Tracking files get onto websites and are downloaded to a computer, in several ways. Often, companies simply pay sites to distribute their tracking files. But tracking companies sometimes hide their files within free software offered to websites, or hide them within other tracking files or ads. When this happens, websites aren`t always aware that they`re installing the files on visitors` computers.

网站安装、下载追踪文件的方式多种多样。通常，公司付费给网站来发布他们的追踪文件。但是，追踪公司偶尔也会将文件隐藏在网站上的免费软件或其他追踪文件或广告中。这种情况下，网站本身也不清楚他们在用户电脑上安装了追踪文件。

Tracking companies are often staffed by math gurus with expertise in quantitative analysis. Some use probability algorithms to try to pair what they know about a person`s online behavior with data from offline sources about household income, geography and education, among other things.

追踪公司的员工多为精通定量分析的数学专家。他们通过使用几率算法，根据了解到的用户的线上行为来推算线下资料，比如家庭收入、所在地和教育程度等。