Bioshock Infinite Plot Speculation (You can move if this isn't in the right place)
Booker Dewitt and Elizabeth escape Columbia, but because of their actions, they are exiled from the United States. On the boat towards Russia, Booker turns toward Elizabeth and says, "You know; you've never told me your last name."
Elizabeth turns back to him, and says, "It's Ryan. Elizabeth Ryan."
Now, before you members obsessed with pointing out the flaws of everyone's theories start replying to this with "this is inaccurate, shame on you", I know that Andrew Ryan's real surname is Rianofski, but it is possible that Elizabeth Russianized (or whatever you call it) her last name to Rianofski. Once again, this is purely speculation.
Huh. I thought people would respond to this.