There is absolutely ZERO reason to use any Google product if you're doing blackhat SEO. Don't use Chrome, Gmail... don't be logged into anything. Don't be Googling your PBNs constantly. Just avoid Google. There is absolutely nothing good that can come from giving them even the possibility of insight into your shady doings. There are a TON of free emails out there that are not owned by Google, MS, or Yahoo. Use those. And there are tons of Good browsers that aren't owned by Google. Would you plan a bank heist next door to the police office? People's stupidity and contrariness astound me sometimes.