At O'Hare Airport, in the United terminal, there's a nice feature above the E-ticket checkin terminals: a display screen explaining to you the security requirements for bringing liquids in carry-on luggage. 3-1-1, as we all now know. (3 ounce containers, in one quart ziploc bag, per one passenger, I guess.) What's awfully nice about this feature is how honest United is about why were are doing this. When they exhort passengers to follow the rules, they don't say "Do your part!" (as in, "let's all chip in to make the process safe and efficient!"). No - they say "Play your part!" (as in, "we all know this is a charade we're performing; please play the role of docile passengers!").