Think twice before you post online. That's the message to the city's police officers in the wake of two recent internet scandals. But the force says it is not, yet, monitoring officers' blogs and Facebook pages. New guidelines on officers' use of the internet outside work are expected to be published before the end of the year, but police chiefs say self-discipline is needed now - and warned of the prospect of disciplinary action if online postings damage the force's reputation. 'Up to now we are trying to heighten officers' awareness about the use of social media,' Paul Hung Hak-wai, the force's director of operations, said yesterday. 'We hope they will [show] self-discipline.' Officers are allowed to reveal their occupation online, Hung told a radio interviewer, but should ensure that anything they post on the internet does not damage the image of the police force. 'If their behaviour or conduct causes harm to the force's reputation, or if it runs against the police's core virtues or commands, they are liable to disciplinary action.' The identities of witnesses or evidence in a court case should not be revealed before legal proceedings are concluded, he said. Pictures showing officers in uniform 'which do not convey a positive message' must also be avoided. His comments came after a female constable stationed in Sham Shui Po was found to be uploading racy pictures to her blog last month. The photos showed a group of female officers pulling up their skirts, pointing handguns at each other and touching one another's breasts. Officers are carrying out a disciplinary investigation, while the blogger, a criminal-investigation officer in her 20s, continues her duties. Last month also saw the release online of 28 police internal documents, including seven setting out police tactics in cases of kidnapping and other scenarios. Meanwhile, crime figures from the first half of the year show that deception cases involving phone calls are on the rise. There were 805 cases in the first half, 26 per cent more than in the corresponding period the same year. Elderly people remain the most likely targets for scams, assistant police commissioner Stephen Lo Wai-chung said. Scammers prey on older people's vulnerability by mentioning family members, he said. 'Once a conman told an elderly woman that her son was kidnapped. She paid him money instantly, forgetting the fact that she had no sons, but a daughter,' he said. Other scam artists pretended to be police officers from the mainland. They told their victims their bank accounts had been compromised, and tricked them into transferring money to the con artists.