I would push the "why don't they keep them in cages until they're 10?!" thought out of my innocent sympathetic mind and try to get my mental peace,which was disturbed by the obnoxious little nudist, back. At a later hour questions like "was the kid lost?" will occur more in the form of curiosity than in that of worry and be automatically replaced by my much more important plans of world domination.
Abduct him and train him to be my evil minion
(Who would just happen to be short,with blond braided hair,dressed up in a long red overcoat and knows Alchemy :P)
Honestly, I'd look and think, "Well, who was the fucking idiot that let this kid go in the nude and run around like that with no adult supervision and not worry about a little thing called pedophiles?" on first impression.
That's probably not good, but it sounds like what I'll do the most. :/