Have you looked at squidGuard? It works with squid and is a rather simple
http redirector. There are some pretty extensive lists of pre-blocked
URLs, it can do some regular expression redirecting, and it's also pretty
simple to add your own lists/rules. It is only URL based, but was a
pretty nice layer of protection I used when at the Boys & Girls
Clubs. It's certainly not a secure means by itself (unless you get
draconian and prevent all http requests to an ip rather than a name) but
it should prevent accidentals like in the example.
You can then not worry about directly editing the stream, but rather
redirect them to a page that you build, or whatever. You can redirect to
any site you choose.
Might be worth a look :)
Wes
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