Here's the thing I got 2 White Hat sites.... However one is now going GREY HAT (i.e. link buying) The other one is staying squeaky clean If the Grey Hat site gets marked as a link buyer and gets hit by the Google Hit Squad... can my other site get penalized as well..... since its on the same IP etc. and Google can tell its mine (they already can tell somehow both are listed under the same analytics webmaster tools accts all of a sudden)
You talk about the human decision, and I think it is different in different cases. If they are after you, they will hit your second site no matter on which IP. I think that the IP case is more the problem of host, or internet provider, so if Google sees not one, but several abusive sites on same IP, they should punish IP somehow, as the host allows spammy sites.
Don't worry your second website will not be penalized by Google. There are hundreds of website hosted on one single IP, if one of the website is penalized it doesn't mean that the other websites hosted on the same IP will also be penalized.
Now here's the thing... Google already knows I own both sites without me telling them... Because one day I logged into analytics..... and there were 2 links to click under one account...... and the 2 links went to both of my websites The All-Knowing-All-Seeing-Google-Eye somehow knew.. So if they see one site that is a Grey Hat... and one that is a White Hat.... will they attack the White Hat for being affiliated with the Grey Hat?
The white hat one might not affected easily if you ensure this will remain clean. But it is very risky so better keep things clean for both of your sites.
For 2 years ive been White Hat... and all it does is get me to the 2nd page Well, not anymore Im getting to the top of the first page If they wanna take my site out? Well guess what.... I got 10 more on standbuy similar domains ill put them on 100 servers if I have to Im ready for an all out SEO War and buying links is the Atom Bomb
some how google will ban you as "this site related to that site"- if you know what i meant? even though you are not on the same IP nor same server. You may trick google (i am not sure about this though) by register your domain names from different locations, different names ..etc. by all means try to created different entity for each site if you can. I am sure google adsense is NOT using their "Analytic" to find out whether the sites are related or not. I have more than 300 sites in my google analytic account and only 20% of them are really my own sites. All other sites are belong to my clients. Now this doesn't means that if one of my sites got deleted by adsense and all of the 300 sites will be banned too. good luck
Shared hosting have hundreds of sites hosted on the same IP. Google know this and I think that is why Google or other SEs will not penalize a site because of a bad IP. Even if you have a dedicated server, IP will not make your site penalized just because another site from same IP was banned.
make sure that your white hat website hasn't have any connection with the website which is penalized by Google.