Blocking these videos does more harm, than good in my opinion. We don't need to forget, we need a daily dose every day what these 7th century vermic scum desire for us.
Our death.
The problem is that these videos are used by AlQ to recruit. Just as well they are not broadcast. Moreover, we have a presidential election in progress. We will be reminded of 9/11 many times in the next 8 or so weeks.