All those ad process that terminate and stay resident create processes in Opera. I currently have processes that are subframes from google, squareup, openx.net, doubleclick.net, demdex.net, rfihub.com, googlesyndication.com, and doubleverify.com. I often see others, like facebook.com, rubiconproject.com, addthis.com. You can terminate those processes in Opera without losing much functionality, but you might get logged out of your GMail.