Why filter?
An area that I find particularly interesting is that of filtering news. Usenet News is effectively run as a gigantic free-for-all anarchy, where everyone can say whatever they like. This freedom is good insofar as valuable opinions cannot be shut out. Unfortunately, the growth of access to the Internet has resulted in a growth in the quantity of "garbage" that is contributed, creating a painfully high signal-to-noise ratio. Some parts of the noise actually discourage participation by people with valuable opinions.
Oh, for the good old days when David Sherman, author of The Practitioner's Tax Guide (and clearly one of the cognoscenti in the realm of Canadian taxation) would do regular postings on can.taxes. He, and many other valuable Internet contributors, have often been driven out, not just because people keep asking the same old "dumb" questions, but because idiots with "agendas" target him with the blame for everything that they wish to criticize about the Canadian tax system.
There was a statistical theory that if you gave a million monkeys typewriters and set them to work, they would eventually come up with the complete works of Shakespeare. Now thanks to the Internet, we now know this isn't true.
90% of messages are "crud"
Sturgeon's Law: 90% of everything is crud. (And that often underestimates things!)
Let the computer reclassify information
Whether it's "type in the classification," or "Drag 'n Droop," it's most effective if I don't have to do it.
How do we filter?
The Government Forces us, Header/URL rules, Text Search, Cooperative methods
Mail Filtering
procmail, .maildelivery, Ifile, adcomplain
News Filtering
Kill files, Score files, adcomplain, Ifile, newsBot
Web Filtering
cookies, advertisements, Junkbuster, WebFilter ...