Opera is based in Norway, which has some of the strictest privacy law in the world. Your data is probably safer with Opera than with your own ISP.Opera becomes a giant proxy server, i.e. all your pages have to transit through the Opera servers bandwidth and may be recorded.
And yet you trust your ISP?Yup, and thus I would never use it. I don't trust any company that much.
Opera has a great track record when it comes to privacy and security.