Like @yebyen said in a sibling comment, satire and parody are protected and comcastroturf is pretty clearly satirical, even if it is pointed, critical satire.
Another comment further down on this post also references a few legal precedents protecting domains that demonstrate protection for domain names along the lines of <trademarkedname>sucks.com
Basically, if you're offering a product in a marketplace and benefiting from consumers' familiarity with the trademarked brand then you're probably in trouble. But if you're not, then you're probably okay.
Another comment further down on this post also references a few legal precedents protecting domains that demonstrate protection for domain names along the lines of <trademarkedname>sucks.com
Basically, if you're offering a product in a marketplace and benefiting from consumers' familiarity with the trademarked brand then you're probably in trouble. But if you're not, then you're probably okay.