Concerning one point of disagreement concerning policy formulation in the above discussion I would suggest that the normal approach is Yes knowing something to be untrue is generally accepted as a reason to tag or remove material In fact the extreme argument which I do not have much sympathy with is that questioning un sourced material is always acceptable no matter what the intention But then people generally add some proviso when arguing this extreme version such as except when we are talking about obvious behavior issues Trying to formulate what less extreme people think I would say that believing something to be unlikely to be something that people could come to a consensus about being true is a valid reason for tagging or removing material This is perfectly consistent with our real way of working verifiability the ability to confirm that something is what rational people could agree to be true is our threshold for inclusion but not personal opinions about what is true