Mumbai, Jan. 8 :    Mumbai, Jan. 8:  Armoured vehicles with global positioning systems, ultra-high frequency wireless networks with round-the-clock control rooms, undercover agents and sniffer dogs to protect clients like Bill Clinton, Steven Segal and Shah Rukh Khan. These all but define the private security agencies in the commercial capital - a Rs 1,500 crore business, booming even when most other businesses are going bust. In the post-December 13 scenario, demands for private security have grown with growing threats to VIPs. And the agencies expect a sharp rise in revenue. Gone are the days when securitymen from private agencies were sitting ducks, armed with nothing but batons. The private agents rely today as much on technology as human intelligence to protect their burgeoning list of clients, many of them from the corporate and entertainment worlds. 'Our business is no longer based on the old chowkidar concepts. We have come a long way,' said Vikash Verma, managing director of property guards, which had helped police with the security of Clinton during his last visit to the city. The agencies now had a 'trained and motivated manpower backed with sophisticated communications and security systems', Verma said. As crime and its modes became more and more brazen over the past decade, private security service went high-tech. As a result, some of these agencies are 'the envy of' the police when it comes to modern technology. With its ultra-high frequency radio network, Property Guards, which among its clients count Hollywood stars Segal and Richard Gere and Shah Rukh, boasts a 24-hour control room, with base stations across the city. 'Our wireless network is much more superior to the police's. In fact, we help them out whenever they ask for our service,' Verma said. Topsgrup, a Rs 65 crore agency, recently launched a fleet of armoured trucks equipped with global positioning system to carry cash. The bullet-resistant vehicles, fitted with closed circuit television cameras, can be stopped by a remote-controlled device in the event of hijacking. 'These armoured vehicles have added a new dimension to the private security business. It is so important these days to transfer huge cash safely from banks to ATM centres, from shopping malls to the bank,' Topsgrup chief Diwan Rahul Nanda said. Verma said the agencies often put a stress on technology because 'you can bribe people, but you cannot bribe machines'. But at the same time, the agencies are bolstering their 'human intelligence' networks, a security concept the private agencies ignored earlier. Trig Guard Force uses undercover agents routinely for the protection of visiting VVIPs. 'Our boys did such a good job during Clinton's visit to Bombay Stock Exchange that not even a fly escaped our attention,' an official said. The business has grown steadily over the past decade, with the number of private security personnel nearly touching 2,00,000, five times as many the number of Mumbai police personnel. Analysts said the business is poised for a quantum growth in the years ahead because of new security concerns following the Parliament attack. 'The VIPs and celebrities are turning more and more to private agencies because they have now realised police alone cannot provide them with security,' said an office-bearer of the Security Association of India, a body of some 200 private security agencies. A police officer said they routinely called the top-notch private agencies for help because they were 'better equipped than us and provide us with the manpower we lack'. The private agencies, however, have one grouse: unlike the police, they are not allowed to use sophisticated weapons. 'We hope this will change when everything else is changing in matters of security,' an agency owner said.