fan-fiction is much more brutal genre. Normally it involves all the famous people, but one could recall the Macronympha fan-fiction from Troniks, hehe...
I guess noise has so much less "fans", but when we think even the smallest underground metal, the fans are uploading videos on youtube for bands. Making animations, slideshows or even more complex, just for spreading the stuff. I think it used to be pretty normal that people did for example their own band shirts, and didn't wait the label or band to produce one. I used to hand paint on shirts and other clothing when was teenager. Now things have changed especially in the metal scene, and it seems like people who in old times could have been into doing things for themselves and possibly couple friends, are now the guys, who actually don't do exactly the "fan art", but also cash in with silly bootlegs. You can see "extremely limited edition" shirts, hoodies, mugs (! haha), etc. sometimes with the "fans" design, sold for highest bidder. Suddenly no more "fans", but some parasites who make quick money on bootlegs or wish to gain popularity for themselves while leeching on bands. I hope the REAL fan-enthusiasm would be based simply on worship of the bands, with no such gaining mentality attached to corrupt this otherwise decent phenomena.
Almost same with punk. While DIY used to be one of the core issues, I think there's now lots of these merchants who may not ask THAT much for shirts, but they simply promote idea where all sides of music must be commercialized and in the end there is "consumer" who's role is just to pay.