A PROTESTER has been charged with possessing a prohibited item inside the G20 security zone. POLICE won't reveal what the 25-year-old was carrying, but media reports say she and another woman were detained by police for carrying a gas mask and a Leatherman knife. The younger woman, 20, has not been charged. Both women have been issued with exclusion notices, preventing them from being near G20 events. "The women came to the attention of police during a protest at Roma Street," police told AAP. The Roma Street people's march is the biggest scheduled protest on the sidelines of the G20 summit.