FTP programs with multiple users
Is there an FTP program that allows multiple users to log in, but that restric each user to a different set of files?
For example, lets say that I log in to the address 188.8.131.52 as User1, I would be able to see User1's files. If I log in to the same IP (184.108.40.206) as User2, I would only see User2's files, but not User1's files.
In a sense, I want to be able to have one address for multiple accounts.
P.S. That IP address is fictional.