It's a parent's worst nightmare. Their child doesn't come home one evening and is missing for several days.

如果有一天晚上，自己的孩子没有回家，然后接下去几天都踪迹全无。这对父母来说，是最可怕的噩梦。

When a 14-year-old boy from Atlanta, Georgia disappeared earlier this year, his mother turned to her smartphone for clues using an app called Family Tracker that helped track his location.

一个来自美国佐治亚州亚特兰大市的14岁男孩今年早些时候失踪了，他的母亲用自己智能手机上的一款名为“家庭追踪系统”的程序来帮助找出他所在的方位。

It is one of several apps that allow parents to track the whereabouts of their children.

这是让父母能追踪孩子所在地的几款应用程序之一。

"You can see where your loved ones are without having to call or bother them," said Roberto Franceschetti of LogSat, the creators of the Family Tracker, which has more than 100,000 users and is available worldwide.

这种“家庭追踪系统”是由LogSat公司创建的。该公司的罗伯托•弗郎西舍提说：“你无需打电话或打扰孩子就能知道你心爱的宝贝在哪里。”这一系统有超过10万用户，可在全球范围内使用。

Parents can track the location of their child on a map, send messages, and even activate an alarm on the phone remotely.

父母们可以追踪到孩子在地图上的位置，可以发信息，甚至能远程激活电话上的警报器。

"We have an option for the sender to make a very nasty, noisy sound. It's a loud siren and we repeat that sound every two minutes until the person picks up," he said.

他说：“我们提供让发送者启动非常刺耳、吵闹的声音的选项。这是一种很响亮的警报声，我们每两分钟就会重复一次这种响声，直到接收者接电话为止。”

Parents don't need to own a smartphone to track their children. The service is also accessible via the web, as long as the phone that is being tracked is running the app, which runs on an iPhone or Android devices.

父母们没有智能手机也能追踪自己的小孩。这项服务也可以从网上获得，只要被追踪的手机运行这一程序即可。该程序在iPhone或Android系统的手机上都可以运行。

Family Tracker has an additional service that keeps a log of all data generated by the app for a two-week period, which the company calls GPS breadcrumbs.

“家庭追踪系统”还有一项服务，能保存该应用程序在两周内产生的所有数据记录，公司将其称为“GPS面包屑”功能。

The service was used to find the missing boy in Atlanta.

该服务被用于寻找亚特兰大的失踪男孩。

"With a subscription, we keep all the locations where people have been on our servers. You can see where your kid has been for the past two weeks. You can find out where someone was at a certain time, or when that person was at a specific place," Franceschetti explained.

弗郎西舍提解释说：“只要您预订这一服务，我们就能为您保存服务器上所有的行踪数据。您可以看到过去两周内您的孩子曾去过的地方。您可以查明某人在特定时间所在的地方，或者某人出现在特定地方的时间。”

"When somebody gets abducted, usually whoever does this throws the phone away or takes the battery out. We were hoping that our app would at least provide information on where the person was abducted or where they had been in the past, that way the police would have a history or some clues as to who they may have been seeing."

“如果某人被劫持了，通常劫持者会把手机扔掉，或将电池取出。我们希望我们的应用程序至少能提供劫持发生地，或被劫持者曾到过哪些地方等信息，这样警察对于被劫持者可能见过的人会有些线索，或能从档案获知。”

But are these types of apps an invasion of privacy?

但是这种类型的应用程序是否侵犯了隐私权呢？

"The advantages are huge compared to the disadvantages. Let's not forget that the person always has to give initial permission — no one can be tracked unless they allow someone to do it," said Franceschetti.

弗郎西舍提说：“相比坏处而言，好处要多得多。不要忘了首先都得获得被追踪者的许可才行——除非自己允许他人这么做，否则谁也无法被追踪。”