[michaelt]

  I'm just saying that tether has
  worked for years, and the peg
  seems to be still there.

A parachute that has "seemed to be there for years" is all very well - but evidence it's fine when no-one pulls the ripcord doesn't tell us what'll happen when someone does.

And if it's a parachute, what happens when someone pulls the ripcord is kinda the most important thing :)