I returned from Europe recently and when I started unpacking I was in for a rude awakening! My 2 spare drone batteries had been removed and held by the Swiss authorities, along with my professional ENG camera battery!? I have been flying all over the world for 20 years with professional equipment and the same kinds of batteries and never an issue until now. The drone batteries are cheap compared to the $700 Anton Bauer broadcast battery. They won't ship them back, they will store them up to a month until someone pick them up in person. Just plain nuts. They were in a professional case that is designed to fly batteries and pro equipment. Now the battery in the drone was still there. So here are the "rules": 1) Batteries can fly IF they are attached to the equipment. 2) Lose batteries cannot fly in checked luggage, even in approved cases. 3) They can fly loose or attached as carry on. Now what sense does that possibly make? Well, this is about a $1,000 loss it appears. To go back and get them costs more than the batteries and I don't have anyone close enough to pick them up for me. Grrrr.... I flew twice earlier in the same configuration in and out of London with NO issues as usual. So be forewarned. Carry your batteries on board with you!