According to US law, what's against the law is intercepting communications that are not readily accessible to the public. A Wi-Fi beacon containing an SSID is n

According to US law, what's against the law is intercepting communications that are not readily accessible to the public. A Wi-Fi beacon containing an SSID is not a communication intended for somebody else, so there's no legal issue with receiving it. The restrictions are on how the hardware is used, not what it's technically capable of.