|English: KOLKATA WEST INTERNATIONAL CITY SCAM (Photo credit: Wikipedia)|
Why would somebody do that? To speculate, there could be a few reasons like just being a troll, attention starved (typical with famous people), or trying to gather information from your friends. I suspect it's the last one in this case.
So what can you do about it?
Not much. Facebook allows for anonymous users and as long as they aren't harassing anyone or posting nude bodies with your had Photoshopped on them, they won't take it down.
However, you can minimize the damage.
Once in a while, do a Facebook Search for Yourself. If you discover that you are a target, see if their friends list is visible. If it is, go through it and contact all your friends about the problem and encourage them to unfriend the impersonator. You could have them report the page, but like I said before, it's likely they won't take the page down.
There are a lot of scammers out there that will use the information of your friends to convince you that they are your friend who is in trouble. This is why I suspect this person was targeted. OR it could be that they plan on targeting any of her friends. This is why it's important to warn all those who friend the imposter.
Watch your email and take care of phone calls that say that someone you love is at risk and needs money. Don't answer any phone number you don't recognize and let it go to voice mail. If you do get something distressing in voice mail, then call the person that is supposedly in trouble directly.
If you have any information on impersonators who aren't celebrities, then post in the comments below. This is pretty recent, so I'm only going on speculation and theories.
If you think you have been scammed, check with the local law enforcement.
More on this when I can more research.
In the meantime, the related articles below have all kinds of interesting info on scams.