I have one Google username that has a public profile and that I use for account registration etc. I have another that I use for personal email that is private.

I have one Google username that has a public profile and that I use for account registration etc. I have another that I use for personal email that is private. I assume more people will start doing the same if they are privacy conscious. Searching this database is no different to searching on Google itself. The only concern would be having a mass email list, but spammers have had those for years and filters sort that out.