Of course they can't, but they conceivably could reduce the spread of material that stupid people are going to use to hurt themselves (or their kids).
First off, they don't have to censor, they could just stop recommending these videos, and that would help a lot.
Second, if you seriously can't see why a for-profit corporation restricting content that literally leads to children being poisoned and dying isn't anywhere near Orwellian, then I am afraid that we have nothing further to discuss.