What do you mean, poaching?

Digging the foot of the wall means digging the lower half of the wall, so that the whole wall collapses. Metaphor is a neutral word. Nowadays, it refers to digging up the relevant personnel and technology of competitors, so as to maximize the benefits. Now some also refer to the object of stealing friends, of course, this is not in line with the original intention. Nowadays, people often use "as long as the hoe is well swung, there is no corner that can't be dug down" to describe falling in love with someone and stealing him (her). Note that it is often wrongly written as "digging a corner".