Sorry to tell you this but the artwork for the socket came from shutterstock: http://www.shutterstock.com/pic-86299162/stock-vector-world-... (turn the socket 180 degrees).

Why is this a problem? Shutterstock does not allow it's artwork to be used in logo's. See legal: You may not use any Image (in whole or in part) as a trademark, service mark, logo, or other indication of origin, or as part thereof , or to otherwise endorse or imply the endorsement of any goods and/or services. http://www.shutterstock.com/licensing.mhtml