Interviewees sometimes make it clear before an interview that, as far as they are concerned, a certain subject or certain areas are “off-limits”.
It’s worth a try, but don’t bet on interviewers playing the game. They can even turn it into a deadly weapon – “I know you don’t want to talk about XXX, but what our viewers want to know is…”. You are then left with the option of refusing to talk about the issue (in effect, offering a “no comment”), or trying desperately off the top of your head to deal with a matter which you considered out of bounds.
A much more effective approach is to be open to all questions, demonstrating to the audience that you have nothing to hide. If the interviewer then strays into what you regard as dangerous territory, you have the option of explaining that you cannot answer the question – and explaining why you cannot. That may be because of client confidentiality, not wanting to give away information to competitors, or not being able to disclose key figures before an annual report. As long as you have a rock-solid reason for not giving a full answer, the audience will understand and accept your reticence.
Remember, trying to steer the interview before it has even started is simply handing the interviewer a weapon….plus the ammunition.