This is a question I'd like to know the answer to also. Haven't found any on the Leupold website.
I did find this on the site though:
Exclusive to the VX-7™, just give the SpeeDial™ adjustment dials a half turn, and each smoothly slides outward for adjustment. Knurled for an easy grip, they offer 20-MOA of adjustment per revolution, and even feature unique, field-interchangeable BDC dials. The adjustments are both easy to read and reset to zero, and offer ¼-MOA, finger-adjustable clicks for absolute precision. Once set, simply push the adjustment dials back in place and give a turn to close them. Additional turns will lock the dials in place for secure adjustments; the integral cap provides a highly secure stow position. The titanium nitride/stainless steel adjustments offer incredibly tight tolerances and near perfect engagement of the interior surfaces of the windage, elevation, and parallax adjustment dials. The result is incredible precision, as well as the outstanding strength and durability needed for a lifetime of repeatable accuracy
Maybe the turret movements are stiff enough that they won't accidentally move due to pulling it out of a scabbard, or case, or ran against the seat of a pickup. But I've seen two different people miss easy game shots due to an accidental rotation of the windage or elevation knob. One was using a new Nikon, the other an old Weaver. Neither person knows how it happened, just that it "was way off".