Description:
All curOp entries now have an "effectiveUsers" section, which is an array of usernames of the users whose permissions apply to the op. Additionally, curOp entries from shards include a "userImpersonators" section, which is a list (usually just one item with the __system user) of users that are impersonating the identity of the effective user.
Engineering Ticket Description:
It would be useful to have authentication information for each operation in the results of currentOp. In particular, the database and user.