On my last flight from Heathrow. I got to watch someone have a royal hissy fit because apparently she thought this was just like the TSA and if you had three pieces of luggage, you could have three baggies - when they told her no she cried.
For those who are American understand that’s not what the USA rules say. It’s just that the TSA is not paying attention. I’ve seen them catch someone , it was my other half, I just stood there and laughed, and then I had the decency not to tell him I told you so.