Latest In Web Tracking: Stealthy 'Supercookies'
Major websites such as MSN.com and Hulu.com have been tracking people's online activities using powerful new methods that are almost impossible for computer users to detect, new research shows.
The new techniques, which are legal, reach beyond the traditional 'cookie,' a small file that websites routinely install on users' computers to help track their activities online. Hulu and MSN were installing files known as 'supercookies,' which are capable of re-creating users' profiles after people deleted regular cookies, according to researchers at Stanford University and University of California at Berkeley.
Websites and advertisers have faced strong criticism for collecting and selling personal data about computer users without their knowledge, and a half-dozen privacy bills have been introduced on Capitol Hill this year.
Many of the companies found to be using the new techniques say the tracking was inadvertent and they stopped it after being contacted by the researchers.
Mike Hintze, associate general counsel at MSN parent company Microsoft Corp., said that when the supercookie 'was brought to our attention, we were alarmed. It was inconsistent with our intent and our policy.' He said the company removed the computer code, which had been created by Microsoft.
Hulu posted a statement online saying it 'acted immediately to investigate and address' the issues identified by researchers. It declined to comment further.
The spread of advanced tracking techniques shows how quickly data-tracking companies are adapting their techniques. When The Wall Street Journal examined tracking tools on major websites last year, most of these more aggressive techniques were not in wide use.
But as consumers become savvier about protecting their privacy online, the new techniques appear to be gaining ground.
Stanford researcher Jonathan Mayer, a Stanford Ph.D. candidate, identified what is known as a 'history stealing' tracking service on Flixster.com, a social-networking service for movie fans recently acquired by Time Warner Inc., and on Charter Communications Inc.'s Charter.net.
Such tracking peers into people's Web-browsing histories to see if they previously had visited any of more than 1,500 websites, including ones dealing with fertility problems, menopause and credit repair, the researchers said. History stealing has been identified on other sites in recent years, but rarely at that scale.
Mr. Mayer determined that the history stealing on those two sites was being done by Epic Media Group, a New York digital-marketing company. Charter and Flixster said they didn't have a direct relationship with Epic, but as is common in online advertising, Epic's tracking service was installed by advertisers.
Don Mathis, chief executive of Epic, says his company was inadvertently using the technology and no longer uses it. He said the information was used only to verify the accuracy of data that it had bought from other vendors.
Both Flixster and Charter say they were unaware of Epic's activities and have since removed all Epic technology from their sites. Charter did the same last year with a different vendor doing history stealing on a smaller scale.
最新研究显示，MSN.com和Hulu.com等大型网站一直在使用功能强大的新方法跟踪人们的网上活动，而电脑用户几乎不可能察觉。
Linda A. Cicero/Stanford News Service斯坦福大学研究员、博士候选人梅尔(Jonathan Mayer)这种新技术是合法的，比传统的“cookie”更厉害。Cookie是网站例行安装在用户电脑上的一种小文件，能够帮助网站追踪用户的网上活动。据斯坦福大学(Stanford University)和加州大学伯克利分校(Stanford University)研究人员称，Hulu和MSN安装的是一种“超级cookie”(supercookie)文件，能够在用户删除常规cookies后重建用户的资料。
网站和广告主已经因在用户不知情的情况下收集电脑用户的个人数据而招致猛烈批评，今年美国国会已经出台了六项隐私法案。
被发现使用这种新技术的许多公司都说，跟踪并非是故意进行，在研究人员联系他们后他们已经停止了跟踪。
MSN母公司微软公司(Microsoft Corp.)副总法律顾问亨兹(Mike Hintze)说，当我们得知超级cookie的问题时，我们感到担心;这不符合我们的意图和我们的政策。他说公司移除了微软创建的这个计算机代码。
Hulu在网上发表声明说，公司立即着手调查和解决研究人员发现的这些问题。Hulu拒绝进一步置评。
先进跟踪技术的流行表明数据跟踪公司改造技术的速度之快。《华尔街日报》去年对主要网站的跟踪工具进行研究时，这些更强大的技术大部分尚未广泛应用。
但随着消费者对保护网上隐私越来越精通，这些新技术似乎开始获得优势。
斯坦福大学研究员、博士候选人梅尔(Jonathan Mayer)在Flixster.com和Charter.net上发现了这种名为“窃取历史记录”的跟踪服务。Flixster.com是一家影迷社交网站，不久前被时代华纳公司(Time Warner Inc.)收购。Charter.net是美国有限电视运营商Charter Communications Inc.旗下网站。
（责任编辑:实习飞刀）
