If the judge is really determined to put you in jail he will find CP, cocaine and unpaid taxes everywhere in your life. Law operates beyond logic and reason: only authoritative opinions and scripture interpretations matter. Ask that question to those who will put handcuffs on you, not to fellow peaceful citizens.
How is that related? If someone puts CP intentionally into the block chain that has nothing to do with math. The spread of child pornography is a criminal offense and they could just force every miner to split the chain or charge them for spread of CP.
> By that logic you could make anything illegal, legal.
I'm not a lawyer but from a technical point of view it's almost impossible to remove any kind of data from a truly distributed network. Be it Bitcoin's Blockchain, BitTorrent or the internet itself. That's just a fact, no judge order will change it, sorry.
And as M4v3R said it'd be very expensive to add a big file like a picture to Blockchain anyway.