Last year, Apple made changes to the way its iPhones report user activity.

去年，苹果对iPhone报告用户活动的方式进行了调整。

The ring sends the information it collects to an app, which rates the quality of the user's activities.

该指环会将收集到的信息发送到应用程序，应用程序会对用户的活动质量进行评估。

Like its main app, Facebook said in a statement about privacy that Campus can use a user's activity " to show more relevant content, " including advertisements.

与主应用一样，脸书在一份关于隐私的声明中表示，脸书校园能利用用户的活动" 显示更多相关内容" ，包括广告。

Because according to Apple's developer guidelines, apps must request explicit user consent and provide a clear visual indication when reporting, logging or otherwise making a record of user activity.

因为根据苹果的开发商指南，手机程序必须明确请求用户同意，并在报告、记录或以其它方式记录用户活动时，提供明确的可视指示。

These make it harder for iPhone apps to track users' online activity, which in turn makes it harder to serve them relevant ads and see whether they work.

这使得 iPhone 应用程序更难跟踪用户的在线活动，进而更难向他们提供相关广告并查看它们是否有效。