Since Riven moderated it and didn't say what it showed, I dont know, keep that in mind.
Talking about german media/internet law, since thats the only I had training in.
Looking at these materials and possessing them is actually a crime, which you just admitted to commit.
Looking is never illegal by german law, possession can be, but thats pretty rare.
Your browser cache now contains these materials, which means you have these files in your possession.
By german law this is not
the case, as many ruling have showed. It is a technical detail that is a byproduct of "streaming" and streaming by definition is always allowed, which includes copyrighted movies and stuff. (I know in Japan this is not the case)
But they can just confiscate your PC, put the files on there and say you had them. What are you going to do ?
Call me an idiot, but given how the police treats people with such files, even after deletion, and how it may totally destroy your life, I'd destroy the harddisk. No kidding. You wouldn't be the first to end up in prison over a 'mishap'.
If anyone and/or the police has a reason to get you, I totally agree. ( Again not knowing what the content entails, but I can imagine)
Also by destroy, just if anyone would actually need to, I would recommend scrambling first because if you just smash it with a hammer you could recover it, but a complete randomization of all the bits would be more safe.
To answer the question
why arent those with power doing something ?
Well those with power, even or especially those that claim to be 'just' only have their own interests and are not at all interested in making the world a better place
by now, like 20 years after the fact, due to snowden finally its out in the opening whats going on with the NSA...
Its actually very simple: Why would
they help ? Looking at it purely logical and without morals. If it benefits you and you can look like a hero on the way, sure, but why if there is not reason too.