1) "because blogging is not an educational use of school computers."
2) "he found the prospect of students putting information on the Internet, potentially available to predators, was a serious concern."
Well, let's not throw out the technology when it's not the technology causing the problem! First, blogging CAN be an educational tool. ANYTHING (almost) can be an educational tool if used and applied the right way. Can cell phones be educational? Sure--if students use GPS-enabled phones to go on a virtual scavenger hunt. Can spoons be educational? Sure--if they are used in an object lesson of some sort. Almost anything can be educational--you just have to be creative!
I believe blogging is an especially powerful educational tool for encouraging reflection and discourse, both of which are well-researched principles of effective learning. You may not agree with me, but even if you don't, I maintain EVERYTHING can be an educational tool if used right. So if you don't think blogging is an educational tool--then dig a little deeper.
Point 2. Why ban blogging because kids put their info on the web? That's a problem with the students, not the tool! You might as well ban phones, email, a lot of things...
I always find it interesting that there is a backlash with new technologies--immediately accusing them of being bad because they are not understood.