You buy a determined amount of minutes for videochating. On your account statement will be shown only this neutral description of transaction:Netdebit/PX24

Netdebit User-Support - Netdebit Userservice E-Mail - Service number: +49 (0)2427 90350-10

All Videochats will be charged on your phonebill.

If you got a Paysafecard, you can recharge your accout using this card. This way is anonymous as well.
With T-Pay you can pay via your phone bill