Blocking Offensive Material(??) with Firewall

[Di Phelan <diphelan () email net au>]

Hi There

I'm writing a paper on our govs currently proposed legislation <OZ> for
blocking offensive stuff on the internet.  A few questions spring to
mind, the two first ones being "How?" and "Does the government have any
idea how the internet works?".

It seems to me that there are two ways of content blocking - at the ISP
level with application level filtering using proxy servers and at the
BSP level with packet filtering using routers.

Both of these methods cause major problems in the form of performance,
accidental blocking of legitimate content and easy circumvention of
proxy servers, routers and schemes like tunnelling.

I understand that proxy servers can block all the sites on a blacklist
and firewalls block all sites that aren't on an allowed list.

Any opinions about how proxy servers, routers or especially firewalls
could be used for content blocking would be much appreciated.

Di Phelan