It's a good question and I wish I had a good answer for you.
Basically, this situation only comes to mind if (a) you are editing your Kunena profile and (b) if you have a template that displays that information. The Blue Eagle template for Kunena does not display that information.
The other requirement is that someone actually uses those fields and enters something into them. Therefore, if people don't enter any information in those fields, no one is really any the wiser.
Having said that, the question (I suppose) could be asked "is there any way to prevent people from entering information in those fields?" or "is there a way I can hide those fields from view in the Kunena user profile?" The answer is yes ... but it's not easy to do.
In effect you need to edit the Kuenena template PHP source code, comment out the lines that are used to display that information, and then you'll have your answer. Perhaps someone else has already solved this issue with their own customised solution and you can also search the form (use keywords like "hide profile fields" or something like that) to see if there have been solutions already posted. Off the top-of-my head, I can't remember whether this has been done before. To be honest with you, most people are more concerned about not being able to enter any information instead of the other way around.
Another way around the problem is to use an alternative user profiling system, such as Community Builder, and deny access to the Kunena user profile. That would also work. I hope that helps.