This article is missing a ton of new information about this issue.<p><a href="https://www.cntraveler.com/story/new-tsa-approved-3-d-scanners-mean-you-can-keep-your-liquids-in-your-bag" rel="nofollow">https://www.cntraveler.com/story/new-tsa-approved-3-d-scanne...</a><p>The whole reason for the rule is that X-Ray machinery uses object density to help figure out what materials are inside your luggage.<p>(This is a gross simplification of a different article I read on this subject, don't trust me to be 100% accurate in my terminology)<p>Some airports have more advanced X-Ray machinery where it can be extremely accurate to the point where it can distinguish water and other liquids from explosives.<p>But in many/most airports, they just have to ban liquids because the machinery can't tell the difference between water and explosives.<p>It's a pretty simple and logical explanation, and I think the rules make some level of sense given the fact that there was an actual attempted security breach involved with making the rule in the first place.
Also a problem is that these rules have business profiting from them. TSA contractors, PreCheck, Clear, Global Entry...<p>So you will have lobbies fighting against any ease in regulations as the more complicated is the check, the better for them.
Let’s put aside security theater for a moment<p>One good thing these rules seem to have addressed is people should pack less things including liquids in their carryons. The side effect though is you get things like you can’t bring things like large liquids that maybe you got on a trip back.
I find some of the examples to be strange and self-inflicted problems.<p>In one example of the couple who travels internationally a lot and complains in being limited in what they can bring, they mention that they only like to take hand baggage.<p>Well, if you check your bags in, then you can take all these things.<p>So it seems like some non-trivial subset of travelers want to insist on not checking bags AND complaining about the rules.<p>This feels a but unreasonable to me.<p>Frequent travelers would often have credit cards that reimburse you for baggage fees. So what’s the problem? You have a choice.