I've heard different things about this. Some of the things I have heard. Using whois guard can negatively affect rank, registering for more than a year can help, using fake info can have negative affects. I have tried all of these and can't say if they hurt or help. I prefer to use whois guard (via Namecheap) and Cloudflair for DNS which I do on some sites without any noticeable change in the SERPS. Please post any results you have seen, both negative and positive. I'm curious.