If you look at the concept of Wikipedia, Facebook, etc., these are platforms that allow people to freely edit and distribute with proper attribution. In the end, this is a good thing because smart developers with a creative mind are creating content that links back to the original sites (Stack Overflow, ServerFault, Super User) - if they follow the rules of course. I've seen sites do this to great effect (like
Why not allow people to freely use the content?
How will smart developers be limited by closing off content?
Is it worth the time to police all sites using the content?
Can you be certain sites like
efreedom are just 'scraping' Stack Overflow? What if they have a legit copy of the database and were smart enough to write a system to display the information?
In the end, those that do it right with proper attribution are just creating more link power for the original sites. I do agree that 'leeches' who are just looking to make a quick buck and hide attribution are clearly against the terms outlined. But I say give smart people who get things done an opportunity to leverage this wonderful CC Wiki open content.
If they are doing it, then ask yourself, "Why not you too?"