近日，美国第六巡回上诉法院法官宣称，针对手机发射出的信号进行追踪可以认为类似于监视一个人在公共场所活动（if a device emits a trackable signal, following their location is similar to watching someone move about in a public space.），这样的表述可以认为是对于手机信号进行合法追踪的认可。
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