Hmm, I not entirely convince anyone is stupid enough to have a blog the lines of:
"Dear Blog readers,
Today I tied up 6 kids in my basement. Tomorrow I'm thinking of bombing a major government building. Down with the government! I sure hope no one spoils my ultra-secret anti-social activities."
I've heard some pedophiles keep catalogues of kids they have abused in the past, but I've never heard of one keeping one in the public domain. I don't know, I guess it wouldn't hurt though. I don't have anything against monitoring of things in the public domain as long there is a good reason to do so. For example I wouldn't like the idea of being monitored just because I might express anti-government sentiments in the public domain. However if I was later a suspect in a terrorist attack or something such monitoring would be fair game.