They are getting popular here in the US as well.
You can buy a used cargo container for $2500-$3000 here, delivered!...............
Sure, it's part of the silly microhousing movement. A musician I knew as a kid got some publicity because he's built a cap for his pickup bed (used to be a common thing to do out here among the hardworking poor farming communities) as if it were some sort of choice -- he really just lost everything on a very stupid 'investment'. Give me land, lots of land...
homes from cargo containers:
homes from horse trailers: