“Since the article doesn’t specify whom the ‘security person’ works for, it’s hard to say what authority the pilot has”.

I know you tried, but you still made the Grammar Nazi very sad. I’m proud of you for attempting to use “whom”, but if you don’t know how to properly use a word, then it’s a good idea to simply avoid it; substitute something you do know. Correct usage (i.e. usage which would not make me cringe) would be, “…for whom the ‘security person’ works…” If you should ever find yourself in a situation where you have the words “whom” and “for” and would like to use them in a sentence, but aren’t certain where they ought to go, just remember Donne, or even Hemingway: For Whom the Bell Tolls. If a 17th century English poet or a 20th century American writer don’t do it for you, and you need something a bit more modern (and tasteless), try Metallica. Whether you choose to avoid the word or not, for the love of all things grammatical, stop putting the “for” at the end of the sentence! I don’t care whether some modern American usage website says it’s somehow okay to end sentences with prepositions such as “for”, “at” and “to”; it makes me sad and makes you look like an illiterate fool. It’s even worse when you try to use a semi-formal word like “whom” along with it, so just…don’t. It’s not at all difficult–watch…

• Since the article doesn’t specify for whom the “security person” works, it’s difficult to judge the authority of the pilot. (Look ma–no cringing!)
• At whom was the shot directed? (If you end a sentence with “at” I will immediately think of Jeff Foxworthy, as in, “You might be a redneck…” Do you really want that to happen?)
• I don’t know to whom the book belongs, therefore I am unable to return it to its owner. (Double whammy–I even got the possessive pronoun correct. No “it’s”!)