apt-get remove --purge fail2ban 
Reading package lists... Done
Building dependency tree       
Reading state information... Done
The following packages were automatically installed and are no longer required:
  gamin python-central libgamin0 python-gamin python-support
Use 'apt-get autoremove' to remove them.
The following packages will be REMOVED:
  fail2ban*
0 upgraded, 0 newly installed, 1 to remove and 2 not upgraded.
After this operation, 426 kB disk space will be freed.
Do you want to continue [Y/n]? y
perl: warning: Setting locale failed.
perl: warning: Please check that your locale settings:
	LANGUAGE = "en_US",
	LC_ALL = (unset),
	LC_CTYPE = "UTF-8",
	LANG = "en_US.UTF-8"
    are supported and installed on your system.
perl: warning: Falling back to the standard locale ("C").
locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannot set LC_ALL to default locale: No such file or directory
(Reading database ... 164647 files and directories currently installed.)
Removing fail2ban ...
Purging configuration files for fail2ban ...
Processing triggers for man-db ...
Processing triggers for ureadahead ...