The telecommunication industry has been successfulin turning the Internet into a mobile service and stimulating the creation of a new set of networked, remote services. In this paper we argue that embracing cloud computing solutions is fundamental for the telecommunication industry to remain competitive. However, there are legal, regulatory, business, marketrelated and technical challenges that must be considered. In this paper we list such challenges and define a set of privacy, security and trust requirements that must be taken into account before cloud computing solutions can be fully integrated and deployed by telecommunication providers.