On one hand, copyleft licenses are a creative form of copyright to enforce the wishes of the author to allow derivative works under the condition they are also distributed freely. Let's call it weak copyleft, the pragmatic variety.

OTOH are copyright abolitionists who are offended by the notion that their freedom to copy and modify code on their own harddisk could be restricted by a mere "license", to them the notion of intellectual property is poppycock. The Strong Copylefties consider GPL a necessary evil, a way to use their enemies' tools against them, to spread their ideals of free culture amidst a corporatist hellscape.

Or it could merely be someone taking the naïve reading of "anti-copyright"