Probably an 8. The best strategy IMO is just to minimize the amount of data anyone has about you (particularly companies that can sell that data or otherwise abuse it for profit) because once that information is out there it just takes one leak before it's public.

So use alias information wherever possible and take advantage of masking services (e.g., for email and IP address). Avoid social media or only use it with hardened privacy settings. Eliminate device tracking and services that require you to be logged in when using them.