Exactly Simon, child porn and terrorism are the two magic words that give politicians basically the right to introduce legislation that was completely unthinkable in the free world even 5 years ago.
Even the Dutch national police has a filter list that get's distributed to ISPs. And although there's currently only one ISP that subscribes to it, the scary thing is that DNS requests for one of those servers is leading you to a page hosted by the police. Conveniently logging your IP address since you apparently sought 'verboten' material.
It's just a matter of time until other ISPs are strongarmed into using the list as well, because they'll just be blamed of 'pushing child porn'.
Dutch article about the filter list.