In the multi-user shell node case, a malicious user with @root@ access could access other user's Arvados tokens. Users should only be given @root@ access on a multi-user shell node if you would trust them them to be Arvados administrators. Be aware that with access to the @docker@ daemon, it is trival to gain *root* access to any file on the system, so giving users @docker@ access should be considered equivalent to @root@ access.
In the multi-user shell node case, a malicious user with @root@ access could access other user's Arvados tokens. Users should only be given @root@ access on a multi-user shell node if you would trust them them to be Arvados administrators. Be aware that with access to the @docker@ daemon, it is trival to gain *root* access to any file on the system, so giving users @docker@ access should be considered equivalent to @root@ access.