When does an answer deserve a "thumbs-down?"?

Question

Is it when the answer is one you don't agree with?
Is it when the answer is inaccurate?
Is it when you don't like the answerer?
Is it when the answer doesn't really answer the question?

When do you give an answer a thumbs-down?

Answer 1

Some instances for me:

I give a thumbs down when the answerer didn't pay attention to the question and wrote unrelated baloney.

When the answer is narrow-minded, lacking diplomacy or not well thought out.

When the answer has an advertisement in the response that is unrelated to the question.