The curse of round numbers: How to get your liquids confiscated.
The air travel industry is in fear of liquids these days, and so the EU is heading for the same bright system that the US has: A small amount of liquids is permitted in carry-on luggage, in small containers, and to limit the total amount, you have to put it all into a ziplock bag. (There go the 3l of bottled water that I normally take on long-haul flights...)
To make things real fun, though, the system isn't really the same: US rules say "no more than 3oz", EU rules say "no more than 100ml"; US rules limit the zip-lock bag to 7.5"×8", EU rules say 20cm×20cm. All of these are nice, round numbers, and they are about the same. But just about the same: That 100ml roll-on deo that is fine in the EU is clearly above the 88ml that you can take aboard a plane in the US, and the ziplock bag dimensions aren't really the same, either.
In reasonble company, the differences are on a scale where it doesn't matter. But would you want to trust airport screeners to be reasonable these days? I'll bet that we're going to see any number of EU ziplock bags confiscated in the US before this gets any better.