Here's a story of Christmas cards the arrival of which at their destination has been long delayed. They were sent in 1941. The reason for the delay is that they were written by German soldiers occupying the island of Jersey at the time and were stolen as an act of defiance:
The group of young men who "liberated" the letters from the German field post office on Jersey did so in an "act of passive defiance against the enemy," the UK museum news portal Culture24 wrote when the letters were donated to the Jersey Archive in 2006. The Germans had been on the island for some 18 months, and resistance to the occupiers was growing.
"V for Victory signs had begun to appear and small acts of resistance began to occur to disrupt military rule," says a statement from Jersey Heritage, the organization responsible for the island's historic preservation. "Many islanders were prosecuted in German courts for insulting the authorities and there is no doubt, had the young men been caught taking the letters, they would have been severely punished."
The main letter thief has since died. His middleman, who held the letters for some 66 years before contacting the Jersey Archive, wishes to remain anonymous.
It looks like only a small act of resistance, but as Hannah Arendt wrote in a related context, nothing of this kind 'can ever be "practically useless", at least, not in the long run'.