Greetings from Finland. No deposit required for the carts, yet almost all carts are being returned (I can't remember when I last saw one not returned).

It happens: https://www.is.fi/hs-vantaa/art-2000006387011.html

You have to read between the lines on why that is so.

Wherever you are in Finland is more considerate than wherever I am in in Finland. Often when I arrive at my local Prisma there’s an employee outside wrangling abandoned carts.