A friend whose work entails a good deal of airline travel has a story some travelers have experienced. Like all of us, he is subject to the 3-1-1 rule of the Transportation Security Administration (TSA), both at home and in the cities he visits.

According to TSA’s rules, any packed liquids in carry-on luggage must be in a 3.4 ounce bottle or smaller and packed in a single, quart-size plastic zip-top bag. For those unfamiliar with the rule, the policy dictates that this bag must be taken out of the carry-on luggage, separated, and scanned by airport security in a gray bin.

Knowing this, my friend chooses to pack little or no liquids in 3.4 ounce containers and had successfully expedited the whole security process for months. Feeling immune to a 3-1-1 inspection, his expectation of privacy and anticipated “no hassle” comfort level has been reinforced, time and time again, by TSA officers across the country and specifically at his home airport.