Saxum IPLogger is a Joomla! extension. With this you can log the IP-addresses of visitors of a website. The extension consists of a component that appears on the administrator site and three plugins.
The log can be seen on a report. The component makes statistics about the location of users (country and city) estimated from their IP-addresses.
To this process the extension uses GeoLite data created by MaxMind, available from www.maxmind.com. These data are modified monthly, so you should update it regularly which you can do from the administrator site.
You can block IP-addresses with the extension, i.e prohibit to visit your website from those. You can define a list of IPs not to log. This could be useful if you don't want to see your own visits in the statistics.
The component can infer any abuse of registered user names based on the log data. It can be configured that user would receive a warning email (or be blocked), if he logs in too many times or from too many places on a single day. This way it can be found out if more persons use the same username or someone's password is stolen.