Jackson isn't the only security expert who's worried. On Thursday, Sunbelt Software Researcher Tom Kelchner said on his : "According to the Opera Unite Developer’s Primer, 'Opera Unite features a Web server running inside the Opera browser, which allows you to do some amazing things.' We’re betting there [are] some other people who use the Internet who will be doing some amazing things with this too."

Opera it runs Unite within a "sandboxed" environment, which should make it hard for people to jump from Unite into other parts of the PC's file system, but the company doesn't say what steps it's taking to prevent hacked PCs from misusing the service.

A company representative couldn't immediately comment for this story on Friday.