Tectonic Edge

Land

: Add .
, , Sacrifice Tectonic Edge: Destroy target nonbasic land. Activate only if an opponent controls four or more lands.

2010-03-01:
Tectonic Edge’s second ability checks how many lands an opponent controls only at the time you activate the ability.
2010-03-01:
Assuming you can activate Tectonic Edge’s second ability, you can target any nonbasic land with it (not just one controlled by an opponent that controls four or more lands).