In a modern world, is there such thing as a reliable authority? If so, who or what?

There can never be completely reliable authority. Regardless of who or what the authority is, because humans are neither completely good nor evil, there will be those who choose to be reliable as well as those who choose to be unreliable. The best we can hope for is for more who wish to choose to be reliable will make the majority of the authoritarian figures, rather than those who wish not to be, who will then punish those of us who find ourselves in times of need and need dependable and trustworthy authority.