It is pretty unfortunate that people seem to be taking advantage of them. I'm sure straightening these messes out is time consuming and unhappy. They sure aren't writing music or creating in the studio while dealing with this stuff.
Noticed pitchfork and many other articles repeat this same tagline, I like that word inaugural.... "Sigur Rós presented the inaugural installment of their Norður og Niður festival in Reykjavik in December".
...and the Grapevine ran this one back on February 20th:
"Sigur Rós Involved In A Lawsuit Over Millions Of ISK Missing From Concert Revenue"
Hope they have better business support now, they need to catch a break for sure.