Self-organization introduces major challenges to security and trust management in mobile ad hoc networks. In addition, security threats and vulnerabilities include lack of proper authentication, insecure routing and complex mobility and identity management needs. If nodes do not have any prior knowledge of each other, trust establishment becomes complicated. For this kind of scenarios, we propose a mechanism that the nodes themselves should be responsible of their own security - or they could trust certain known nodes, ldquomicro-operators.rdquo In addition, we compare trust establishment in both operator-controlled and self-organized mobile ad hoc networks using example scenarios. In operator-controlled case, a trusted third partner provides central administration for the network via a decoupling point. In the self-organized case, networks are formed without central administration.