Just finished reading a lengthy story at MSNBC about efforts to convince Internet service providers to take a more active role in stopping the spread of child pornography.

Reading that opening sentence, I suspect most people will immediately think these companies should be doing anything and everything to help. And they certainly have some new options, thanks to new technologies and a recent change in U.S. law.

The new law gives Internet providers access to a list of files that have been identified as child porn.

Although the law says it doesn’t require any monitoring, it doesn’t forbid it either. And the law ratchets up the pressure, making it a felony for ISPs to fail to report any “actual knowledge” of child pornography.

The new software is known as CopyRouter. It’s been developed by Australian-based Brilliant Digital Entertainment, which says it can check every file passing through a provider’s servers against that list of child porn files. (Each file has a unique signature that cannot be altered by simply renaming it.)

Banned files would be blocked, and the requestor would receive a substitute file provided by law enforcement, such as a warning message: “The material you have attempted to access has been identified as child pornography.” The attempt to send or receive the file could then be reported to law enforcement, along with the Internet Protocol address of the requestor.

Sound great, right? Well, not everyone thinks so. John Morris of the Center for Democracy and Technology warns that such monitoring would violate U.S. law. No company, he said, has the right to listen in on private communications unless it is ordered to do so by authorities with a court order. Otherwise, he said, it constitutes an illegal wire tap:

“This would be plainly illegal in the United States, whether or not a governmental official imposed this on an ISP or the ISP did this voluntarily. If I were the general counsel of an ISP, I wouldn’t touch this with a 10-foot pole.”

The idea apparently makes some providers nervous as well, with some suggesting that more laws may need to be passed to protect them from liability.

What do you think? How do you feel about having someone filter every file you send or receive? Is there even such a thing as “going too far” when it comes to stopping child porn?