I helped a guy install the cables across some of his land (tree to tree), precisely because the poachers were getting out of hand. He did not have an overhead line running through his property, but instead a gas pipeline buried underneath of it.
He called the gas company and told them he put spike strips out along the pipeline route to stop the poachers. (He spot welded a bunch of nails to a piece of flat steal and put a clevis hook onto one end of it so he could drag in with his truck.)
I know he caught one truck with the spikes, because the guy had to come up to his house to get the address so AAA could send a tow truck. (I do not remember the outcome, but it involved the sheriff and a game warden.
)
I bought a cheapo first gen night vision scope and it only works on bright nights, full moon. Resolution is very poor. I would not recommend it to any one.