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If you use an anonymous SIM card, but a second non-anonymous card is inserted in your device at the same time, the anonymous SIM card is no longer anonymous. This also applies to a second phone that you carry with you.

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As both SIM cards share the IMEI of the phone in the provider's traffic data, the anonymous card can be easily assigned to you.

Also avoid carrying a second phone with a non-anonymous card inserted in it. Since the anonymous SIM card and the non-anonymous SIM card move together through identical radio cells, it is theoretically possible to determine who the anonymous card belongs to. Even if the SIM cards are inserted in different devices.

Particularly important for the following target groups:

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