Desmond Tutu will lead protesters...campaigning against British security firm G4S's role in maintaining prisons and detention centres in the West Bank and Israel. The South African retired archbishop and Nobel peace laureate will challenge G4S's management over the company's alleged role in facilitating "Israel's brutal occupation and abhorrent prison system" at the company's annual general meeting in London...Tutu, and several other notable protesters including directors Mike Leigh and Ken Loach, philosopher Noam Chomsky and barrister Michael Mansfield QC, have written an open letter to G4S management...demanding the company stop supplying equipment to Israeli prisons. "G4S helps the Israeli Prison Service to run prisons inside Israel that hold prisoners from occupied Palestinian territory, despite the Fourth Geneva Convention prohibition of the transfer of prisoners from occupied territory into the territory of the occupier...Through its involvement in Israel's prison system, G4S is complicit in violations of international law and participates in Israel's use of mass incarceration as a means by which to dissuade Palestinians from protesting Israel's systematic human rights abuses." The protesters claim that human rights organisations have documented "systematic torture" and ill treatment of Palestinian prisoners, including children held in solitary confinement, at some of the prisons. In a separate letter...a number of MPs...said children were reportedly ill-treated in the prisons and called on G4S to "terminate its contracts with facilities where children suffer routine physical and verbal abuse". G4S...said it "takes very seriously our obligations to ensure that our activities do not contribute to human rights abuses".