Copyright itself is arguably theft sponsored by the state, because information can naturally be freely used/shared by all of humanity. Creating property rights in information reduces the collective knowledge of humanity (the commons), because now information can't be shared.
The goal of the GPL and viral licensing is to undo copyright as such.
I don't agree with this maximalist approach because many forms of knowledge wouldn't be created without a financial incentive. But there's many niches in the economy where free software creates greater economic benefit than a proprietary solution.