Sorry for the late reply on this.
It's a valid question that has been brought up as there is some ambiguity in terms of what is stated in the AUP. We will work on cleaning that up. Officially, this is our point of view:
Avast, like any other provider of VPN services, must ensure that our customers do not use our services to violate the law, for instance, by downloading copyrighted materials without permission of the copyright owner. We cannot and do not actively monitor for this. However, if we receive a complaint about misuse (for instance, from a copyright owner), we will investigate and take action if the complaint is correct. This is standard procedure for reputable providers of VPN services.