We know linking sites together with the same IP is not has good as unique IPs. We know Google doesn't look highly on people with their "own network" of sites linking together. So people make sure their sites are on different IPs and then link away. But what happens when they use Adsense and Google Sitemaps and have all those sites under one account? Do you think Google looks at this and says hey this person owns all these sites and is linking them together. Thoughts?
I am not sure. The only thing is if you are concerned use multiple accounts. I also have concerns about how google analytics could be used like this.
I don't think Sitemap accounts would make a trustworthy factor. As a webmaster I have a couple of hundred sitemaps in my account but only a few of those are mine. However, interlinking domains is never as valuable as true one-way links. The IP based factor is noted in a patent but I doubt wether this is truely used as a factor to recognize interlinked domains.
For Goodness sake. People are acting like they've got something to hide, like google are their enemy! Or do you have something to hide? If the only links you are relying on are your own interlinks, then you've got bigger problems to worry about. ...like writing or making things people want to link to!