Your investment may be “water under the bridge” but you don’t speak for mine.
The 1960 Supreme Court decision in Flemming v. Nestor, herein the Court held that an individual does not have an accrued property right” in his or her Social Security benefits. The Court has also made clear in subsequent court decisions that the payment of Social Security taxes conveys no contractual rights to Social Security benefits.
Source: http://fpc.state.gov/documents/organization/45221.pdf