I experienced this first hand (and still have it intact, THANK GOD) when I traveled to Saudi Arabi with my Pocket Trumpet. I had it confiscated 3x at airports I traveled through at the time (in 2014). Each time, it was returned to me by a superior agent after I had the chance to plea with them that I only intended to practice the horn in the privacy of my hotel room with a silent mute attachment (that I took out of the case and showed them). In each case, the horn was returned with the warning not to play in public.
I did play it once, during a celebration party of my visit, way out in the desert after I thought I had silently walked away from the host, where I played Caravan. As fate would have in, several host diplomates followed me out into the desert (unbeknownst by me) and heard me playing. I turned around to see applause. I returned from that party, hands intact.