Tax revenue. That's what every state is about.
On a related note -- a couple years ago I get notice from the state of RI that I never filed my 1990 taxes and owe them $1,300 between fines, etc. So the past few years they snatched my refunds.
This year I decided I want receipts from this point forward, and I'll keep my tax records for more than three years so I can prove I filed. Turns out the RI Division of Taxation won't give a receipt. I got the woman to stamp my copy with their "RECEIVED - RI DIV TAX" verbiage with the date and all.
Hopefully the state will lose one more of my returns -- then I can bring the receipted version to the news hounds and watch as the sparks fly.