We were checking in at 6:15 am today 11/20/2014 at the first Alaska Airlines ticket Skycap counter outside SEA. An elderly woman was rifling through her bag, and a $100 bill was on the ground. My sister picked up the bill and wasn't sure if it was ours, or the elderly woman's. She politely asked the elderly lady if it was her $100 bill. The lady responded no. The SkyCap attendant immediately grabbed the $100 bill out of my sister's hand, and proclaimed in an assertive manner "I'll take that!" I was appalled by that behavior. That money was either ours, or the old womans, but I was not in a position to challenge the skycap attendant. I'm really feeling upset about it, and not sure who to forward my complaint to. I submitted a complaint with Sea-Tac online, but not sure how far that is going to get me.