RRSPs and the GIS

The Guaranteed Income Supplement (GIS) is a low-income benefit for those collecting Old Age Security.  It is based on income.  Seniors withdrawing from their RRSPs can see almost a dollar for dollar decrease in their GIS.  A taxpayer challenged this and said RRSP withdrawals should not be used in the calculation.  The Tax Court of Canada did not agree with her and determined RRSP income should be used in the calculation.