Because one time when I returned back to US from a vacation the U.S. immigration officer asked me too many personal questions and when I asked why she needs to

Because one time when I returned back to US from a vacation the U.S. immigration officer asked me too many personal questions and when I asked why she needs to know my employer and it's location she yelled at me that she has this right. I didn't know at the moment that they do not have this right. Next time I just wanted to make sure I am recording my conversation with the officer I saw the "no cellphone" sign. So yes, you should be allowed to record any conversation with government officer to protect your privacy better