What satisifes you for tying down?

[abgd]

Obligatory reference:

BBC NEWS | UK | England | Tyne | Concrete block fell from aircraft

That said, I'm not sure tie-downs are as useless as people seem to think. From my hang-gliding days, you can hold down a light aircraft sized wing in 20-30 mile an hour winds with just a few lb of force so long as you don't let the wind pick up a wing or lift the nose to increase the angle of attack... in which case things will get out of control very quickly. I think this is where tie-downs are likely to be useful: just in keeping the initial stages of stopping the wind getting under a wing.

[Romeo Tango]

I take the view that if the wind is strong enough to move my aircraft (Robin, MTOW 1150Kg) it will move any lumps of concrete it is tied to.
If it's tied securely to the planet with wire hawsers then a high wind will strain the tie down rings on the aircraft enough to damage the aircraft anyway.

Sometime there are circumstances where one aircraft can blow into another so it's just neighborly, but mostly I don't bother.

[9 lives]

I landed at a Manitoba airport many years ago, where the winds were reported as high, but diminishing to an intensity I would accept for landing at my arrival time. When I taxied in, I saw four aircraft lying on their backs, apparently from the strong winds which had just passed. Three had tie down ropes attached: Two had 5 gallon pails of concrete tied to the ropes, one had coiled screw in ground anchors freshly pulled out of the soil, and the fourth showed no ropes. One, a Champ, had hit an otherwise undamaged aircraft which was effectively tied down.

That was one of the events which got me thinking to the effectiveness of tying down, and our moral duty to our fellow pilot/owner.