• by Wendy Davis , Staff Writer @wendyndavis, April 9, 2008

There has been much debate recently about whether Internet service providers should filter their networks to prevent users from uploading or downloading copyrighted material.

Hollywood and record company execs have touted such a plan, and at least one network operator, AT&T, said it's considering deploying filters. Digital-rights groups condemn the idea, arguing that networks shouldn't be in the business of censoring content. In addition, they say filters can easily be defeated if people encrypt material.

Now, a new study has found that filters are indeed fooled by encryption techniques. NewTeeVee.com reports that a test conducted by Internet Evolution and French music industry group SNET showed that detection rates of some filters ranged from zero to 50% when traffic was encrypted, depending on the type of encryption used.

Yes, the people who develop filters can probably figure out how to account for encryption techniques. And those determined to upload pirated material will devise yet more sophisticated methods.

This escalation can continue indefinitely without making much of a dent in piracy. Meantime, if networks start censoring material, in a misguided attempt to stem copyright infringement, there is no telling what legitimate material will also be cut off at the pass. Many people currently make fair use of copyrighted material -- by including clips as part of a review, for instance.

Given that filters can't tell whether a use of copyright is lawful or not, and can't detect when pirated material has been encrypted, it's hard to see what good can come from deploying them.