An objective algorithm is pretty much impossible on this topic, at least one that does anything useful. Hate speech itself, for instance, is subjective, so ANY judgment on such will also have to be subjective. Fake news is also a problem as there is no way for the system to know what is not fake in an objective way. Since political bias is so big a component of fake news, you can't really trust any organization as a source as we all have political leanings. You can trust that which is repeated the most, but that just means the lie that gets repeated the most gets trusted as well. Trying to be an arbiter of Truth is a lost cause from the start.