Even the most familiar people can be easily impersonated online by a determined scammer.

Edythe Schumacher was tricked online by someone posing as her own sister, msnbc's Bob Sullivan reported on his "The Red Tape Chronicles" column Wednesday. She lost $2,000 in a wire transfer that the impersonator encouraged her to make.

"I would never have sent the money if I didn't think it was my sister," Schumacher told Sullivan. Her real sister had even warned people by email that her Facebook account was hacked, but Schumacher did not read that email until after she sent money to the impersonator.

The scheme is a modern variation of the "grandparent scam," Sullivan wrote. Scammers typically call elderly people, pretending to be grandchildren in need of money. Online, this scam is easier to pull off, since someone in control of a person's Facebook account would be able to see the names of relatives and other details that would make the scam more convincing.