Predictive dialers drive increase in silent and dropped calls

Automated calling systems, known as predictive dialers, are causing an increase in silent calls and dropped calls across Germany and Switzerland. These systems are designed to dial multiple numbers simultaneously, often exceeding the number of available agents in a call center. When a recipient answers and no agent is free, the call results in a “lost call” where silence prevails, or a “dropped call” where the connection terminates abruptly.

Authorities, including the German Police Crime Prevention unit, warn that these silent calls may be used by scammers to identify active phone numbers. By answering, users inadvertently confirm their number is valid, which can lead to increased phishing attempts, unwanted advertising, or the sale of contact information on the black market.

To mitigate these issues, experts recommend answering unknown numbers with a simple “hello” and hanging up immediately without further questioning if there is no response. Users can also utilize technical countermeasures such as built-in smartphone spam filters, blacklisting specific numbers, or using services provided by telecommunications providers to block suspicious number ranges.