So I think peg-leg is just panic-mongering; it's not going to happen any time soon.
Only the fringe fiscal Conservatives seriously pursue anything like that, the Social Security system as it is now is so embedded in the retirement calculations of virtually all working Americans, including the career military, that it's inextricable. Many things about it may be adjusted, including tax rates, eligibility age, or even means testing, but the core of it just has far too high a percentage of the working population (and their families) too deeply invested to back out, and since it's run as constant revenue-in/benefits-out system with no bankroll, it's not financially possible to cash out a hundred million contributors to wind it up.
It's a pipe dream of some hard-core fiscal geeks, and a perennial bogeyman for the Democrat politicians to use to scare the Medicare crowd. It ain't gonna happen.