Should I keep this check?

During December 2009, I filed for unemployment. There was a big delay processing my claim, and I finally got a piece of mail from the D.C. unemployment office yesterday. I thought it would be some generic piece of mail saying they closed my case or something, but it was a check for $600 for the period ending December 15th.

I found a job in late January and stopped filing weekly claims. Legally, am I entitled to keep this check? Morally, should I keep it? I really needed the money then, but now… it’s just icing on the cake. I know there are people who could really use that $600. The D.C. government isn’t that efficient- would giving the money to charity be better? What would you do?