i never thought about it... i always considered poaching to be:
killing game out of season
killing game illigally at night
killing game illigally from a vehicle
those always seemed like they fit the description of "poaching" best... although i guess you guys are right, poaching can be through tresspassing, and many other illigal means...
but i personally wouldnt use the word "poaching" if everything was legal except the land they shot it on... i would just say, "oh that guy tresspassed to shoot that deer" ... i wouldnt say "oh he poached that deer" ... i dont know why, even though its considered poaching, i guess there are different situations where i personally feel the word "poacher" fits better, like the ones i mentioned above..
at least thats my opinion....... not that its right in any means......lol