Mrs. Doubtfire?

After his mother died in 2003, Thomas Parkin forged documents and filed lawsuits in his mothers name and also accepted social security benefits and even posed as his mother in meeting with authorities and at banks. What The EFF man? Eventually he was dscovered...there's a shocker but it wasn't until he had racked up about 100K and 6 years worth of shenanigans.

http://www.cnn.com/2009/CRIME/06/17/ny.mother.impersonation/index.html