There are so many meanings to words, variations in doctrines, that to take a 'person' and make a 'challenge' against him results in a lot of negativity ill defined, confusing, and containing so much inconsistency of connotations, that it is not well advised.
Why not have threads about 'errant doctrines' and challenge and define them, and if this preacher or that one is guilty of them, they will then be recognized without us having to name any names herein...
a man may have sinned via preaching errant doctrine last week, repented this week, and attacked here next week... it was the doctrine that is wrong, the errant preacher would now be in the good graces of the Lord, and we would be then 'accusers of the brethren'.
I do not like threads attacking preachers by name... for that reason... let's attack the false doctrines, for they are always false, cannot repent and be made right..... but people can! We can mention that at some point a certain person preached or taught that doctrine, but we are not able to know that person's current relationship with the Lord, to make judgments on him/her at this moment...
my opinion is to avoid these 'personal' attacks, even if we feel they may be well based and truthful, and attack the false doctrines that some people may have...
notice herein that the attacks tend to get onto the 'personal' area, and the 'false doctrines' seem to get bypassed, ill defined, misunderstood... and the end result is the person is tagged, and not many even understand the 'why', or the errant doctrine of which they are accused... Is there any value to that?