I don't know... on one hand... it will probably just be used to sell ads... but what if it actually worked? like, maybe some small dent in the rate of suicide?
Assuming that it works (and I don't think I'm emotive enough that it would) I don't think cat pictures (no mater how efficiently they're distributed) can put a meaningful dent in the kind of depression that would lead to an act of suicide or even genuine sadness.