You does not read comments there. Read last comment:
"Tried this on Squeeze for apache2:
# apt-get install libapache2-mod-security
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package libapache2-mod-security
So tried your one:
apt-get install libapache-mod-security
Which was installed into the mods-enabled dir.
Sadly, your Sec* entries above fail:
# /etc/init.d/apache2 restart
Syntax error on line 219 of /etc/apache2/apache2.conf:
Invalid command 'SecFilterEngine', perhaps misspelled or defined by a module not included in the server configuration
Action 'configtest' failed."
That could be problem if i do this. Because I need a tutorial for this.