Flapcake wrote:It's free but you may not use it for anything
It's "free for personal use". That means you can use them for personal, non-commercial use, ie. you may not profit from them.
CC maps are considered commercial use, as lackattack makes money from this site, even if the mapmaker personally doesn't profit from his map.
It's the same with fonts, by the way. When you look for fonts to download, you have to check that it's completely free, or public domain. If it's marked as "free for personal use" then you can't use them on CC maps, or any other commercial projects.