Just because you do not declare it on your incoming form, customs officers can still pull someone over for an inspection just like they have always do. So imagine for pofiling sake, that every solo male of any age arriving in from BKK,HKT,SGN,DPS should be a candidates for coughography breaches.
So what defence does someone have if there is (legal) cough on their laptop, yet they don't tick the magic box? Could it lead to a $225 (or whatever the current amount is) fine from Customs for not declaring something? What if the laptop was used by a colleague/family member who downloaded cough without the owner's consent.
What if cough was downloaded by accident - ie a pop-up advert occurred while web surfing showing coughographic material?
The question by customs is way too broad. I think it's funny that they specifically ask about "illicit drugs" (rather than just 'drugs'), yet won't expand on their definition of cough.