It can, but it's a very different device. Rather than preventing the vehicle from starting, OnStar talks to the engine computer and can slowly reduce power, or

It can, but it's a very different device. Rather than preventing the vehicle from starting, OnStar talks to the engine computer and can slowly reduce power, or, yes, cause it to come completely to a halt. But OnStar is also careful about when and how they do it. See, for example, this story where OnStar waited for confirmation that the cops were directly behind the car: http://www.theblaze.com/stories/2012/07/18/cant-just-shut-it-off-anywhere-onstar-stops-stolen-camaro-during-police-chase/ http://www.theblaze.com/stories/2012/07/18/cant-just-shut-it... Or this story about the slow down feature: http://www.autoblog.com/2007/10/09/onstar-debuts-stolen-vehicle-slowdown-service/ http://www.autoblog.com/2007/10/09/onstar-debuts-stolen-vehi... So basically, OnStar can shut down moving vehicles, but they only do it with the involvment of police (as far as is known). Whereas the auto loan ignition interrupts cannot shut down moving vehicles, but can be triggered with no oversight. Apparently.