Its basically patent- trolling with ground. You buy enough to stop any construction process, dead in the water due to legal processes.
Now you can extort from any company going there, wanting to build something the money for the little area you sell + the money it would cost to restart construction elsewhere - 1$ + the legal fees saved by not going to court.
ProTip: You might want to share the wealth with local legislators later upon, to avoid having zoning-laws changed.