科学美国人60秒 社交媒体网站可以分析你的联系人（在线收听）

When you install an app on your smartphone, you’re often asked whether you’d like to share your list of contacts with that app. That might be a convenient way to connect with friends and family likewise using, say, Instagram or Whatsapp, but it also means you’re giving away their personal information to the app developers.

每当在智能手机上安装应用程序时，都会被询问是否允许该应用程序读取你的联系人列表。该功能可能会你在使用Instagram或Whatsapp这样的社交软件时，更方便与朋友和家人联系。但这样做同样也意味着，你将他们的个人信息透露给了应用程序开发人员。

And that personal info could end up being used to create so-called “shadow profiles” of your contacts—even if they don’t use that app or social media service.

而那些个人信息很可能最终会被用来创建所谓的“影子档案”——即使那些人并不使用该应用程序或社交媒体服务。

Shadow profiles emerged as a potential problem in 2011 when an Ireland-based advocacy group accused Facebook of gathering information on non-users, including names, email addresses, phone numbers and physical addresses.

2011年，影子档案成为一个潜在问题。当时一个爱尔兰倡导组织指责脸书收集非用户的包括姓名、电子邮件地址、电话号码和居住地址在内的信息。

The following year researchers showed that social network companies such as Facebook could use machine learning to pretty accurately predict whether two non-members known by the same member also know one another. Not exactly Big Brother, but a recent study in the journal Science Advances raises the stakes.

第二年研究人员发现，像脸书这样的社交网络公司可以通过机器来精确地预测，认识同一人的两个非会员之间是否也互相认识。虽然与《老大哥》并不完全相同，但最近发表于《科学进展》杂志上的一项研究再次引发担忧。

In that work, David Garcia, chair of systems design at the sci-tech university ETH Zürich, used a social network member’s personal information to infer relationship status and sexual orientation of the members’ contacts who did not have their own user accounts on that social networking site.

在这项研究中，苏黎世理工大学的系统设计主席大卫·加西亚利用某个社交网络成员的个人信息，来推断此人联系人中并没有该社交网络用户账户的某个联系人的感情状态和性取向。

He was able to do that using, of all things, data from the now defunct Friendster social networking site. He says he chose those two attributes—relationship status and sexual orientation—because they can carry important privacy consequences and were both available in the Friendster dataset.

而他做到这一切使用的竟然是已经不复存在的社交网站Friendster上获取的数据。他表示，选择感情状态和性取向这两个属性，是因为它们对个人的隐私拥有重要影响，而且这两种属性都能在社交网站Friendster的资料库中获取。

Garcia is careful to point out that he didn’t prove that shadow profiles exist, just that they can be created. His work also reminds us how much we wind up revealing online—about ourselves and about the people in our lives.

加西亚谨慎地指出，他并没有证明影子档案的存在，只是证明了它们能够被创造出来。他的研究也提醒了我们，自己在网上暴露了多少自己和生活中其他人的信息。