Methods for managing and blocking anonymous phone calls

Receiving calls from suppressed or unknown numbers can present both a nuisance and a security risk, such as phishing attempts. While not all anonymous calls are fraudulent, users are advised to remain cautious and avoid sharing personal data, passwords, or TANs during unexpected calls.

To manage these calls, Android and iOS users can utilize built-in settings to block unknown callers. On Android, this is typically found within the phone app settings under 'Blocked Numbers'. Additionally, services like Tellows offer spam protection by utilizing contact files of common spam numbers.

For more serious cases involving harassment or threats, German law (TDDDG, Paragraph 14) allows for a technical measure known as 'Fangschaltung' or Malicious Call Identification (MCID). This service, provided by telecommunications providers, can identify the connection used for the call. However, it must be set up in advance, is subject to a fee, and requires a written application documenting the harassment. The Bundesnetzagentur notes that this is primarily intended for threatening or harassing calls, though international connections or manipulated lines can still complicate identification.