A Law firm in America has filed legal claims against Toyota, Ford and General Motors, accusing them of failing to address a problem which can allow a car to be hacked.The Texan Attorney Marc R. Stanley, based in Dallas, has filed the claim.It says there is a defect which allows hackers to wrestle control of the car from the driver.PR Newswire in the US quotes Mr Stanley as saying "Toyota, Ford and GM have deliberately hidden the dangers associated with car computer systems, misleading consumers."The lawsuit alleges Toyota, Ford and GM concealed or suppressed material facts concerning the safety, quality and functionality of vehicles equipped with these systems.  It charges the companies with fraud, false advertising and violation of consumer protections statutes.Electronic control units in cars are connected through a controller area network, referred to as a CAN or CAN bus.  These control units communicate by sending CAN packets 'digital messages containing small amounts of data.  If a hacker can send a CAN packet to an ECU on the car's CAN bus, he can take control of basic functions of the car, including braking, steering and acceleration.