Do they all have direct access to every other device, memory and hard drive connected to your computer. Genuine question, I'm not sure but I would have thought

Do they all have direct access to every other device, memory and hard drive connected to your computer. Genuine question, I'm not sure but I would have thought they have to go through the main processor to access those devices. However with ME and PSP they have complete access to everything you do on your computer. It can record your screen, monitor your traffic, connect to the internet, etc