Doubt-casting

Doubt-casting is an intel trick designed to make either an individual or specific information look bad without necessarily providing any evidence to back up their claim. It could be considered akin to a fallacy, and applies half of an argument is PR.

Usage
Let's say Johnny makes an argument that a corporation should be more transparent with it's financial details citing examples of corruption. A malicious doubt-caster would, rather than rebut the statement, ask what Johnny's true intents are, for example "Why would you want to see a company's finances Johnny?", implying without evidencing or substantiating that Johnny is up to industrial esponage, making people unnecessarily and unfairly suspicious of Johnny without proving any evidence of the given speculation.

By not substantiating their points clearly, it prevents Johnny from being able to rebut their points and allows them to evade or change the definitions or meaning of their speculative inquiries, which of course, casts doubts on Johnny's credibility.

This implies that Johnny may be up to no good with his effort, but without the doubt-caster substantiating his points or providing examples. A classic example is "If you have nothing to hide, you have nothing to fear", implying all people opposed to it have something to hide, and ergo are implicitly guilty without any evidence to substantiate the point.

Doubt-casting is not explicitly against the individual either. The attack may also be conducted against the argument, again, using baseless speculation. Even if Johnny was to supply evidence, a doubt-cast might be "How valid is this argument?", or "Wouldn't this be the kind of argument a terrorist would use?". The difference between skeptism and doubt-casting is doubt-casting is baseless speculation leading to a credibility slur (on either argument or author or both), where-as skeptism has a particular goal of verification. An example of valid skeptism would be: "Do you have any financial documents I could see to check this corruption Johnny?", as opposed to "Isn't this the kind of argument only a crazed conspiracy theorist would use?".

Overlap with Ad Hominem
Doubt-casting shares similarity with the critical thinking fallacy Ad Hominem in that the attack can be made against the author, however, unlike Ad Hominem where definite information is presently adversely against the individual as a red herring, the challenge is presented speculatively, for example: "Aren't you a former politician?", the goal being to cast doubt on the target individual.

However, unlike Ad Hominem, doubt-casting is not strictly limited to the target but also speculation about the argument.

Overlap with Poisoning the Well Fallacy
Similarly, it is also akin to poisoning the well fallacy, in that information that alters people's view is deployed, however, unlike poisoning the well fallacy, it is not deployed pre-emptively and is deployed contiguously through-out a debate even after reasonable concerns are addressed in order to skewer people's perception, for example: "Why are you evading my question about detailing the overly complicated financial processes?" - even if said financial processes have already been reasonably detailed and evidenced.

History
Prime examples of doubt-casting and speculation within history would include McCarthyism and the Boston witch-hunts, in that people who presented views that were seen as adverse to other people were speculatively queried or accused without evidence as being associated unfavourably with specific beliefs. For example, during the period of McCarthyism, people were speculatively asked if they were associated with communists, even if evidence was lacking, which was sufficient to ruin, in some cases, their careers.

Modern day
The usage of speculative doubt-cast applies in the modern day, primarily via the media, who will make speculative queries or questions about people as headline stories (as controversy helps to sell papers as a financial means), often causing 'vigiliante justice' to result, even if said speculative querying is intrinsically false or known as intrinsically false. For example: "Is politician drunkard?" might be speculatively applied.

Similar tactics are employed within intel circles as a form of black propaganda in that speculative slurs about individuals or their information is made in order to discredit, often renting out news article space from newspapers or having anonymous 'insiders' release artificial information, for example, a lot of newspapers speculated heavily on Julian Assange's personal life, casting doubt on him, and thus indirectly, any information he may have released (even if he wasn't the originator of said information).

Counteraction
Establishing counteraction to doubt-cast, one must first verify if a question is a doubt-cast, which is  relatively straightforward: Is the question constructive or destructive? It can be determined to be constructive if it adds anything valid (IE relevant) to the debate or point presented.

If it is determined as destructive (IE is irrelevant, is attacking the author unnecessarily, makes baseless speculation or conjecture, etc), then the motive of the doubt-caster in destroying that argument should first be established, or failing that, clarification in what they hope to achieve by their statement?

Malicious attackers will have no goal other than to destroy the arguments and will be unable to admit as such and will be evasive as to their intents, forcing them off-kilter in the argument's tempo (forcing them on the defensive rather than offensive). This will usually expose malicious intentions for public viewing or at the very least the shallow nature of their inquiry to other people.

If the doubt-caster cannot be made to justify their doubt-cast, then their comment should be acknowledged then dismissed as irrelevant as they failed to justify why it should be answered. Accusations of evasion over the doubt-cast should be met with the observation they refused to validly justify why you should answer an inherently destructive and invalid question.

For example:

Person A: "Are you or are you not a communist?"

Person B: "I see your question, however I refuse to answer as I do not believe it's valid to the debate on the number of people in-debt."

Person A: "You're being evasive, you refused to answer my question."

Person B: "You have not justified why such a question is valid to this debate."

Further attempts or challenges should be ignored as a type of conversation, debate or thread hijacking, in which the refusal to answer the red herring doubt-cast becomes the focus of the debate instead. Individuals should re-rail.