Opt-in to Porn

I want to start this post by stating that I believe that pornography has a pernicious effect on society.  It has extremely negative effects on the development of children and teenagers.  It is as addictive as alcohol and even has negative effects on adults.  That being said I think that it is a bad idea to have the government require Internet Service Providers (ISP) to filter pornography.  

The reasons I don't support it are:

1. It is not currently technically possible to filter all pornography.  There are many consumer products that filter the internet and none of them are 100% accurate.  I have posted previously about K9 Web Protection and OpenDNS as ways to protect families from pornography and other harmful topics on the Internet.  Even using both of these it is still possible to "stumble" across pornography.    
2. If we require ISPs to to filter all pornography then when something inevitably slips through what is to protect them from being sued for not following "law" even though that law is not possible to follow completely?  This will lead to many smaller providers to go out of business thus lowering the competition on the market and possibly cause rates to rise.
3. I am an advocate that the best way to protect our families is by teaching and raising them with our values.  We as parents can protect our children by adding those web filters to our computers and homes, but the first line of defense has to be what we teach them.  

I would recommend a different solution than a government regulation.  How about instead we all contact our current ISPs and request that they put in place Internet Filters and then we can subscribe to those?  It must be remembered that this can only be a "best effort" filter.  There is little more that they can do that 3rd party applications can not do now.

If we can't protect our own families, why should we try to require somebody else to do it for us?

Please comment on this post if you agree or disagree.  However I request that it be kept civil and productive. Don't just say "I disagree" or "I agree", but explain how it would or wouldn't be possible for ISPs to filter the Internet.