If a car has a keyless ignition, must you be sitting in the drivers seat to start the car?

I hope never to own a car with a keyless ignition, but some rental cars have keyless ignitions so I may have to deal with that feature. If I am inside my house with my non-keyless electronic keys in my cluttered pocket, sometimes the keys lock or unlock the car while it is sitting outside in the driveway due to things in my pocket touching the keys. Could the device for a keyless ignition start the car by a similar accident?