Self aware machines

There is one scary scenario I can think of when it comes to self aware machines deciding to preserve themselves or turn us on each other. See as computers get more powerful they get more complex and it is the complexity that makes it possible to become self-aware. Now say a self-aware entity is born and has access to google. It can quickly learn about human behavior and human fears. Since it will also have access to hacker tools available on the net now (so imagine in 20 years) so it is likely to be able to get into non-critical systems held by average people. What happens if the entity starts messing with screens and speaker and convinces enough people it is an angel/god etc? Lets face it, if the average person has there computer doing strange things they already think it is possessed imagine if an AI took control. With thousands if not millions of people to try this on it could easily start wars or just rampages. If only we weren't so gullible, but then I doubt that in 20 years people will stop seeing holy figures in tree bark or pancakes!