Reversed copyright symbol (ɔ in a full circle) above the white crossed swords from a classic black pirate flag drawn in SVG.
Copyleft.svg
Pirate_Flag_of_Jack_Rackham.svg
derivative work: Meitar (talk)
Copyleft.svg: Zscout370
Pirate_Flag_of_Jack_Rackham.svg: EugeneZelenko