Mullvad has been selling these cards at various retailers, one of them webhallen which is both an online and physical store in the nordics. However, many/most p

Mullvad has been selling these cards at various retailers, one of them webhallen which is both an online and physical store in the nordics. However, many/most people in the US get a large fraction of their purchases through amazon. So to sell to people in the US they need some way of doing it. The important bit is that the actual account code is hidden behind on of those scratch panels. So amazon does not know your Mullvad account. Now an adversary with enough geographic information about who connected and access to all of amazon's data could possibly correlate purchases with connections. 10 years ago I would have considered that infeasible, after Snowden I'm not so sure. If you live in a big city it is like still no issue, but if you are in some small town with a population of 1000 things might still be traced back to you. Still it's likely significantly superior than pretty much any other method including using crypto. If you are a possible target of a state actor you hopefully are thinking about this already.