This tutorial explains how to use the Nexmo Call Control Object to make anonymous calls using a Vonage virtual phone number as a proxy. The tutorial covers setting up an application and webhook endpoints, using a Vonage Call Control Object to forward a call between two temporary phone numbers, and demonstrates a real-life scenario where a buyer can communicate anonymously with a seller without revealing their phone numbers. For production applications, it's recommended to use multiple APIs to build a complete solution, such as handling incoming calls, determining the virtual number of the rider, and sending SMS messages to private numbers.