When we manage your site, we will maintenance a ChangeLog for every thing we have doing on your site. Here is an example part of the ChangeLog:

2008-08-25
* Fixed the Joomla template which will expose the Joomla version.
2008-08-20
* Hacked 2 Joomla admin password, already changed it has send a notify email to Super Administor
2008-08-16
* Remove the wirte permission in these files and directories: html/includes/* html/templates/*
* Removed the unused directory which already confirm by Super Administrator: html/xdt
2008-08-12
* Upgrade Joomla from 1.5.8 into 1.5.9
2008-08-03
* Fixed EZ Store Remote Blind SQL Injection Exploit
* Removed the unused template which confirmed by Super Administrator: rhuk_milkyway
* Removed the unused file which will expose the Joomla version: html/configuration.php-dist, html/htaccess.txt