is it possible to find out if a user is sharing his login-name/password ?

Hello,

I have some concerns about fraudulent use of login-accounts.
Is it somehow possible to find out if a user is sharing his account (login-name/password) with
other users ?

Can a user be logged in only from one computer (tcp-ip-addr) or is it possible to be logged in with the
same username from different computers at the same time ?


Thank you,
Philipp

sure you can log the IP address with every login (you need to create some custom code to do that)