I have read several similar questions before posting this. So, please don't mark it duplicate before reading this completely.
Few days ago I tried to logout of my Stack Exchange account. Since I was using Stack Exchange Openid, I also logout from the openid. But instead of permanent logout I was expecting, on clicking login button I was automatically logged in without asking login details.
By doing some research I found that there is a
Local Storage cookie from the
stackauth.com domain that is preventing me from logging out. I then deleted the cookie and I was permanently logged out successfully.
Now, It doesn't make sense if I want to logout from stack exchange, I have to:
A) First logout of the stackexchange site
B) Then logout from openid.stackexchange.com site
C) And finally delete the Local Storage cookie from stackauth.com domain.
I don't think that most of the users are going to do all three steps. Most of them will do the first step and will assuming they are logged out, they will not perform 2nd and 3rd step.
Personally, I feel that step C should be eleminated and user should be warned he might be logged into openid provider.