It was never an investment, nor could anyone who did the least bit of research ever consider it an investment.
The first recipients never paid any Social Security tax. How is that an investment program?
It is a socialist retirement program. People pay taxes to the government, and the government pays out welfare payments. There is no connection between the two actions.
That means they will run through everything they and their employer paid into the system in just under 10 years ($281,520). Live longer than that and they are ‘taking’ someone else's money.
For reference, I got the OASDI earnings contribution cap by year here:
http://www.ssa.gov/OACT/COLA/cbb.html
And the tax rates by year here:
http://www.ssa.gov/oact/progdata/taxRates.html
It was never a sustainable system. At 3.3 workers for every retiree (and that ratio is still headed in the wrong direction), and more economic trouble looking likely in the future, something has to change.