This Column takes a good look at filtering. There are other articles in the same paper Here and a letter to the editor Here, all from the Hanover Mariner, in MA.
"There's a fine line between squelching freedom of speech and First Amendment rights, and protecting minors from potentially harmful material and images.
A broad interpretation of The First Amendment is that it allows people to make choices. Choices about what they believe in, what they don't believe in, and how they want to express those beliefs."