Can I see which Twitter user is currently logged in?

Question

They are not OAuthed with my site but are logged into Twitter on that browser. Any way for me to know their Twitter username? Cookies.. anything?

Answer 1

Unless something is very broken or Twitter has explicitly provided an API for that purpose, no. Not through cookies at least.

Cookies are sandboxed to the domain that created them. No cross-domain access to cookies is allowed.