DUP councillor Ruth Patterson has been charged with sending a "grossly offensive communication" after she made comments on Facebook about a planned republican parade in County Tyrone.
The 57 year old had responded on Facebook to someone else's post about an imaginary attack on the parade in which several Sinn Féin figures are killed.
Mrs Patterson had written: "We would have done a great service to Northern Ireland and the world."
She has since apologised, and the DUP has criticised her arrest and said they intend to raise it with the chief constable.
Mrs Patterson was arrested yesterday morning and was released from a police station in south Belfast late last night.
She will appear in court to answer the charge on August 22nd.