This is inspired by the post by Jillian C. York who's got some interesting links here.
Around the world, the ongoing massacre in Gaza is pushing people to further street protest. Gaza on my Mind proposes a series of banners, freely printable and usable during mass-protests.
Artists inspired by the tragedy unfolding have circulated some copyrightless political cartoons and drawings like those by Mazen Kerbaj:
Cartoons courtesy of "Mazen Kerbaj."
Or these mind boggling cartoons by Carlus Latuff:
Cartoons courtesy of "Carlos Latuff."