I'm not sure about digital storage such as cloud serviced. But for example you decide to but a new HDD/SSD you pay an extra 1.25 SEK/GiB up to a maximum of 100 SEK, or a new mobile phone that's another 4.38 SEK/GiB with no upper limit.
The reasoning behind that tax is that in Sweden you are allowed to make personal copies of media you own and apparently the movie/music industry loses to much money due to that law. So that money will go to the movie or music labels as compensation for lost revenue.
Parent mode, haven't played in a while? Here is a recap of the story so far and here is what you did last time you played.