Is "Superman" a U.S. citizen? If so, how did that happen? Did he show up for his citizenship exam in full cape & tights outfit and give his name as "Superman"? Or did he become a citizen by act of Congress? What about "Clark Kent"? Did he go through the citizenship application process? Or has he been carrying around fake ID - and working in the U.S. - all these years? (If so, INS would like a word with him.) And even if "he" - which in this case means "both of them" I guess - actually is/are citizens: you can't just say "I don't want to be a citizen anymore". You have to file a petition with the State Department, and they're under no obligation to approve it. If he does successfully renounce U.S. citizenship, is he going to take up citizenship somewhere else? (if not, he'll be stateless, which basically means he's illegal everywhere). Batman is way cooler anyhow.