I've just watched the new Richard Heart interview and he gave a short opinion about Chainlink. Watch from 1:24:00, only about 1.5 minutes long. youtube.com/watch?v=N8XItl65QBM
According to him the oracle problem is either not solvable or if solved worth more than any other crypto. The CL whitepaper does mention sybil attacks briefly, but I'm also remembering this Reddit post here, stating that sybil attacks are the single biggest problem to a decentralized oracle network and the solutions from Chainlink won't work. reddit.com/r/CryptoCurrency/comments/75dg5i/thoughts_on_possible_chainlink_sybil_attacks/ Fittingly that thread got no replys. Well, who would know, most of us are brainlets anyway.