I have a confessed "paranoia" about identity theft. It's something clearly rational to be afraid of in the world we know--because it's very REAL. Your identity is tied up with lots of money, and money is ostensibly important.
Yet there is another level of thought about using another identity where we don't consider it to be a bad thing. If you play Super Mario Brothers, you are "stealing Mario's identity" for a while in order to have honest fun. Yet other video games do have notions of characters that you build up where it is not appropriate to use someone else's identity--such as in World of Warcraft, where if you took someone's character that would be considered "stealing".
Though you can enjoy the experience of being Mario, even that has limits. Nintendo doesn't approve of you using Mario's name or likeness in ways that they consider "inappropriate"--so if a manufacturer made "Super Mario Chainsaw Baby Massacre Fest" they would be sued. It actually goes farther than that, as Nintendo will even force people to take down videos of themselves playing the game as it was intended to be played!
Depending on how generously you think about your own life...you might be willing to let someone else try being you. They could adopt your appearance, live in your house, sleep with your significant other...etc! This plot of being able to live in a virtual reality and be someone other than who you "really are" appears in several movies--notably in "Strange Days"--in which it's possible to purchase recorded memories and experience them like you would a movie.
I'm kind of on the extreme of wanting to give conscious beings the freedom to do anything they'd like. I've had heated arguments with people who believe the random-luck-of-the-draw (such as with your genetics) is a good thing because it promotes diversity. Yet usually the people making these arguments do not have missing limbs or other disfigurements! I'd rather take the unlikely risk of living in a world where everyone freely chose to look like Brad Pitt, rather than live in a world that forced someone to draw the short stick. A fair system is more important to me than my own happiness, precisely because I cannot be happy in any situation which was reached via an unfair system.
Kanye West shares the open-minded vision in this ad for Absolut Vodka, although it does point out that the duplication has drawbacks:
My laissez-faire attitude toward letting people do or be whatever they want does have limits. That limit is essentially making sure everyone has the same freedoms, and especially important is that information flow freely and with relevance to what someone is looking for. It's one thing to sing the song "Louie Louie" at a karaoke bar, that's fine. What's not o.k. is to take down the karaoke sign, hoard all the slips, and sing all night pretending you're Richard Berry and putting on a concert--purporting to tell people what the songs mean when you do not know!! Karaoke should be fair, everyone should get to sing and know what they can be.
But sometimes an impostor is who you're looking for. Craig Ferguson has a funny bit about a celebrity who at a low point in his career signed autographs on Hollywood Boulevard pretending to be an impersonator of himself. Yet the people wanted "the real impersonator":
In fact, with the rise of flogs (fake blogs) sometimes the fake blogger is more interesting and more attentive to comments than the person or institution being faked would be. Britney Spears might not care to journal about her life or respond to your comments, but in a role-playing sense someone else might enjoy taking on that role. So I think it's okay if everyone is aware of the game, and if they know how to try and get in touch with the actual artist. It becomes exploitative when the connection to the artist is closed off.
There are many music videos which try to educate people about the dangers of impersonation, and manipulation by those who have greater technology than you do. Here's a short list:
Hot Chip - Over and Over - The band shows a revelatory peek into how a green screen and some motion capture cameras can be used to create several different illusions. One of the best parts, I think, is when they "multiply fans" to take a small number of people dancing and turn it into a large crowd.
George Michael - An Easier Affair - George shows a capture setup that he is dancing in front of, which is clearly scanning him as he is dancing. The appearance of a variety of other dancers seems to me to obviously suggest that these other people are other avatars which could be 3D rendered from the same data of one person dancing--e.g. this video could have been made by a single person. ("It's an easier affair, not living my life with other people"). We're not too far from having technology that good--though we'd suppose that it's merely a vision of future technology that was acted out by a group of distinct dancers.
Pet Shop Boys - I'm With Stupid - Perhaps one of the best examples of amateur identity theft: a couple of dopey looking actors conduct large-scale and badly choreographed versions of Pet Shop Boys videos. The Pet Shop Boys tied to chairs watch on helplessly. Notable here (in my view) are the colored lights and patterns which seem to exist as a sort of out-of-band "metadata"--which those in-the-know can read to suspect it's not "official".
Madonna - Sorry - Though on the surface not a video about identity theft, an attentive viewer would see that it does. Look at 1:25-1:50 and notice that Madonna has inspected someone and realized he is an impostor. I do not think it coincidence that "metadata" lights are reappearing here, in the same vein as "I'm With Stupid".
Culture Club - Time - This video shows an emphasis on how at another level our lives might be seen "outside of time", and focuses on the idea of recording. It ends with all the band members using a remote control to put themselves in the place of Boy George as the singer.
Pet Shop Boys - Wouldn't Normally Do This Kind of Thing - This video shows the Pet Shop Boys playing versions of themselves for the amusement of children, doing silly things, and it eventually devolves into a game of Mortal Kombat. Again, it does allude to an environment ripe for impersonation.
Many more of these. Of course my dreams lead me to believe that the technology to do real-world impersonations and simulated realities does exist--so I see this a bit differently from the way most people would watch them. Certainly the message of "don't be fooled" is there either way.