Hive can be pretty good for checking if someone is who they say. If you are contacted by an account that may appear to be an established Hiver, but the account is new or has a low reputation then you should be wary. You can see who follows them too. On other platforms this may be harder to check.
Indeed, transparency in the accounts may be uncomfortable for those who are used to privacy, but it is beneficial for there to be a balance within the system.
There can be ways to prove yourself without giving everything away, but those who try to cheat tend to get found out.