[TimGremalm]

"When an unregistered user edits Wikipedia, he or she is identified by his or her IP address. These IP addresses are translated to users' approximate geographic location. Unregistered users only make a fraction of total edits -- only 15% of the contributions to English Wikipedia are from unregistered users. Edits by registered users do not have associated IP information, so the map actually represents only a small portion of the total edit activity on Wikipedia."

[kubanczyk]

    s/unregistered/not logged in/

Registered users often don't bother with logging in.

[remram]

I log in, mostly so my IP doesn't get put on blast in the log.

[3pt14159]

I log in. Mostly for nostalgia, (I started the resilience wikipedia page and still regret doing it without an account!) but also for skipping the annoying pledge banners.

[petee]

I'm not sure thats true since it's a policy violation (without proper disclosure) that is fairly regularly enforced when found

[archon1410]

not really. logging out to do certain things is a violation, but simply editing logged out by itself is not a violation. see https://en.wikipedia.org/wiki/Wikipedia:Sockpuppetry#Legitim...

[petee]

My mistake, though as i understand its still frowned upon, further down WP:LOGOUT says a little why

[howenterprisey]

I wouldn't say that's a common practice.

[chronogram]

I always log in to edit, then log out.

[prolyxis]

I log in mostly for the custom CSS.