What exact information does Stack Overflow collect when signing in with OpenID?
What is meta?
- Any Stack Exchange user can ask a question
- The community provides support, votes on ideas, and reports bugs
- Your voice helps shape the way Stack Exchange operates
We record the OpenID identifier (which is a URL almost always), and optionally record an email address and personal name if they are provided. Email and name aren't required, so an OpenID provider that doesn't collect (or send) them will still be accepted.
If an email is provided, we use to connect other accounts on the Stack Exchange network under certain circumstances. This is to make account merging an automatic thing, as people sometimes forget whether they originally signed in with Google, Facebook, etc.
You probably have not yet read about what OpenIDs are:
Following is an excerpt from here