It is possible to create a user account without any access permissions in a web admin interface

[antonsviridenko]

This can confuse customers who will be unable to login as newly created users if they forgot to set appropriate checkboxes "Web Access", "Remote Access", etc. Also it's possible to remove all privileges and save changes on user account.

However it can be useful if admin wants to temporarily disable some user without deleting account.

At least some warning should be displayed