A plausible idea, but just remember that we are having problems with social security now because it is based on age, and a lot more of us are about to enter that age.
A lot of the savings you are talking about are in retirement accounts which have never had income taxes paid on them.
Right well I'd propose giving everyone their SS money back, with interest. If you are 67 today, and have a life expectancy to 80 years, I'd give you 13 years of SS payment in one lump sum. Of course, I would mandate that this money be placed in a lock box of your own, like an IRA, which sets a maximum and minimum withdrawal. This would encourage investment in the economy, protect your retirement money from tomfoolery, take it out of the hands of the government AND prevent all this money from causing inflation.
If you are approaching retirement age, I'd give you all your payments back, with CD rate interest, under the same scenario as above. You must lock it up and protect it, and draw it upon retirement at regular intervals.
If you are younger, I'd give you your SS money back, with interest, under the same restrictions but they will not apply to you after a certain amount of time.
Eventually, say over a 30 year period, the restrictions would slowly (and automatically) strip away so that eventually the entire SS system would be closed and private and secure retirement accounts would be the norm.
That is my Social Security Reform Plan.