At the very least, I cannot understand why someone would have aliases unless the purpose was to conceal ones identity for unwholesome activities.
Why didn't the media check Obama out? That is their job. It is not their job to spread disinformation. Can anyone think of a legitimate reason for someone to have so many aliases? Is it true he had these aliases? What names did he use during which years? Why?
There are reasons. A pen name is an alias. So is your FReeper screen name. (I assure you my name is not "The Cat".
However the form doesn't ask about aliases, but rather other names the person might have gone by. Whenever I fill out security paperwork, I have to add an "AKA", because my father never liked my first name, and always called me by a variant of my middle name. Thus I'm "AKA 'variant'".
In Barack's case he should have at minimum put down "AKA Barry", but also probably "AKA Barry Sotero", maybe Barry Dunham, etc.