SO - login with other user id
58686
Logging out of Stack Overflow or any Stack Exchange site?
110171
How to limit the number of active logins per user?
125402
Run Trigger As A Specific User (or Profile)?
83503
How to add existing user to an existing group?
61677
set session - custom variable to store user id
42631
How can I share a directory with an another user?
143740
When does a login happen automatically?
145911
Run as a different user on a shortcut
57648
Manage another user's credentials for network access
57804
Per User Named Credential and External Identity Users
30157
How do I hide a particular user from the login screen?
101117
Accessing SSH_AUTH_SOCK from another non-root user
461
Can we let users with privileges on one site have them on another?
143710
Can I hook into user registration *before* a user is created?
21275
same user two login - chat username on site x shows SO user name
28787
Proper way to create logins on Always on
33844
How do real and effective user IDs work?