Again, fairly new change, but everyone blocked through the api is currently blocked with +nousertalk enabled.
Check out [http://en.wikipedia.org/w/index.php?title=Special:Log&type=block&page=User:192.0.2.16 this test block ip].
Blocked using 'action=block&user=192.0.2.16&expiry=never&reason=testing&anononly=1&nocreate=1&token=...&format=json'
Cheers =)
-slakr
Version: 1.14.x
Severity: major