Most blockchain currencies are seen as 'trustless' systems, but in fact they trust in profit oriented people who create the blocks for them and meet fundamental technical decisions for them.
So who is validating blocks and transactions in FairCoin? Every FairCoin core wallet obeys the exact same rules and thus only accept data that complies with all these consensus rules. This is one of the fundamental core concepts of decentralised P2P crypto currencies. FairCoin with Proof-of-Cooperation is no exception here. All nodes validate every transaction and block. Thus malicious transactions and blocks that contain such would not be accepted by the network.
Therefore we have set the definition of CVN to Cooperatively Validated Nodes which describes the social process about how they come into existence rather than the function they fulfill. The admins do not watch the CVNs. In fact everybody can watch what the CVNs do and what the admins do - all activites are written to the blockchain into block payloads. Admins only execute decisions met in the FairCoop general assembly.
In usual Proof-of-Work currencies you have to trust the 5~10 mining farm operators who are driven by greed. In the Proof-of-Cooperation system we trust in >20 CVN operators who are driven by honour. If one repeatedly fails, chain admins can replace him or her by a democratic decision process only.