Propaganda is defined here: http://dictionary.reference.com/browse/propaganda
Engaging in propaganda, information used to harm a person or a group, was very common in WW2 in Nazi Germany and many others also engage in it today.
If one is seeking expose a ministry or an individual that is spreading falsehood, they must be able to back their points up and demonstrate such. If they are incorrect on a certain point, they need to be honest enough to correct themselves and instead refute what the person ACTUALLY says, not a caricature of what that person is saying. We all mistakes in haste and need to be willing to admit them.
A propagandist will usually twist facts to sway people to their cause, which is despicable to say the least. This includes defaming a persons character with lies and deception, rather than establish facts about the person, drawn from the individuals actions.
If the person you respond to in question responds, read carefully what they have said and engage the argument. False ministers of the word need to be brought down via the truth, not brought down via lies and propaganda.
Jesus Christ is not honoured when he seeks Christians engage in lies, thus if you are an apologist for a biblical ministry, seek to uphold the truth when you respond to the person, do not engage in deceiving your audience about a person, for that is a wicked way of the world.
Sometimes, but not always, a person can check the claims of the propagandist and realise they have been led astray, when they actually find out what the position of the defamed individual actually is.
Let us be called to a higher standard in all matters of faith and conduct.