text: The Marines need the information, so they can provide it to the civilian agency that will do the background check and conduct the interviews.  If you do not provide the information, then it is possible that they will find it out some other way, through public records, but it will take longer and your niece's security clearance could be delayed, or even denied.  \n\nyes, this is perfectly Legit.  Yes, your niece was the one to ask you, the military is not in the habit of calling random people up out of the blue and demanding identification numbers.  \n\ndeopending on the relationship your niece has with her aunt and how high her Clearance needs to be will depend on whether or not you will be contacted for an interview.  All the Marines are interested in is finding out whether or not your niece could ever be put into a compromising situation witha foreign governmnet\n\n\n\nIf your wife has nothing to hide(she's here legally, etc) then there is nothing to worry about.  Quit being so bloody paranoid.  Be grateful that your niece is serving her country, giving you the freedom to badmouth your president.