[squid-users] Help, Squid ACL regex_url BYPASSS

Dear all,

I would like to ask for help regarding the Squid regex_url
configuration.
Currently, I am preventing my users for downloading some files e.g file
with .bz2 extention.

In squid.conf I define as following :
acl BadUrl url_regex -i "/usr/local/squid/etc/data/BadUrlFile"

Add I add this entry to /usr/local/squid/etc/data/BadUrlFile :
\.bz2$
=20
So for example if my users try to download this URL
http://www.kernel.org/pub/linux/kern...tch-2.0.40.bz2 , he will
got access denied page.

But some of the users did some trick by adding ? or ?/ in the URL, for
example :
http://www.kernel.org/pub/linux/kern...ch-2.0.40.bz2? Or
http://www.kernel.org/pub/linux/kern...h-2.0.40.bz2?/

And they successful to bypass my ACL and download the files they wanted.
I have try to add "\.bz2?$" and "\.bz2?/$" in to
/usr/local/squid/etc/data/BadUrlFile file. But it does not work.

Can anyone help me ? Thank you very much in advance.

Regards,

Herman