My guess since they mentioned the Kista area: Husby, Rinkeby or Akalla. Maybe Hallonbergen. I lived in Solna for a while, studying at KTH in Kista. I've spent a fair bit of time in and around these areas and I can't say I've ever felt unsafe in them. Whenever people talk about these areas as no-go zones or areas where if you enter you'll probably be mugged, stabbed, shot, raped, or worse, I wonder if they've ever been there at all.

I live by Hornstull, my friend lives in Älvsjö near Tussmötevägen and my friend in Kista lives about 10 min from Rinkeby.

It's kinda ridiculous when I see a map where they mark "Enskede" as a no-go zone.