because if you don't everyone would be able to do anything and sometimes you need to be banned or congrulated. that's another reason. they need to know who they are talking to
To log on the IEEE website, you have to register and create your own account. Asking a question like this here is effectively the same as asking for a "hack" or someone else's user name and password....
user name and password is very important because both are used for security purpose .if we have important data in our system than any person can have steal data from your system.so in that situation...
I don't know whether there is a send user name to email or Send password to email but that would work. When you joined you should've wrote it down somewhere that you would remember where it was....