Una búsqueda a sido suficiente para confirmar lo dicho:
Informacion Oficial:
Once you download Opera Max, it instantaneously starts compressing and rerouting data using a Virtual Private Network (VPN) to the data-savings cloud. All non-encrypted data requests (excluding websites and apps with HTTPS connections) are sent through our compression servers, which optimize video, images and websites to use less data. Opera takes privacy* very seriously so Opera Max only measures how much data you use and how much data you've saved.
http://www.operasoftware.com/press/r...ile/2014-02-23
Con esto confirmo lo que suponía, funciona a través de sus servidores, y que dice la privacidad? lo siguiente.
Opera Max Privacy Policy:
Opera receives and logs data traffic including the web addresses, IP-addresses, your device model and operating system version with the purpose of providing the service, to study aggregated user behavior and to improve the services. Opera is not able to link this data to identifiable individual persons.
http://www.opera.com/es/privacy/max
Entre otras cosas dice "estudiar el comportamiento del usuario". Dicen no poder identificar individualmente a una persona, pero almacenan y estudian el trafico de sus servidores, aunque sin identificar a una persona concreta, pueden saber los hábitos de las personas.
AndroidAuthority:
Since the app is essentially a VPN service, you may experience slower web browsing depending on things like your distance from the nearest server. Also, because it does compress data, you may also notice some lower quality images and video.
También como confirmación, del uso de VPN, de peores velocidades de navegación, y peor calidad de imagen y vídeo.