In case anyone else runs into this, I figured out what is going on. We are in the process of moving from using VSO for builds to Jenkins. We will still use VSO for version control. During the transition, both are running in parallel and gated-checkin in used in the VSO build definitions. When VSO checks in code after a gated checkin, it adds "***NO_CI***" to the comment. This is a code that tells VSO not to kick off yet another build. Since VSO is what actually checks in the code, the user is shown as Account Service, i.e., the original user who committed is not passed through. So, if the VSO build definitions are turned off, "***NO_CI***" disappears and the user name of the one who checks in the code shows up.