The account above looks real, right? Bill Keller's name, photo and URL are all correct. Most importantly, his Twitter handle reads: @nytkeller.
Well, it turns out this is actually a fake Twitter account.
After suspecting something was off with the account — namely that it didn't have a little blue "verified" symbol next to it and didn't show an accurate follower count — I discovered that the two "ll"s in the Twitter handle were actually a capital "i" and lowercase "L." So in Twitter's app, it looks like a capital "ll" when in reality it spells his name with an "il." I notified someone at Twitter late last night (see the timestamp of the screenshot) and asked if this was a Twitter bug, or a fake account and they said they would investigate. It turns out, it was the latter.