As long as it is public as to what they are blocking or flagging, then it's better than not doing it at all. The bigger problem is people may not either care or believe something is fake news, just because someone highlights it as such. It would be nice if there were questionnaires with people's voting, so post-election we could see how much understanding or knowledge different groups have; you couldn't, at least initially, put any weight on what someone's vote is worth based on this of course.