If it was that easy and would not cost so much, they would have done it already.
The reason proposals like this aren’t already enacted is because the cost outweighs the benefit. Do they make more money by spending this money? Keep in mind that if they spend the money and you’re wrong, it causes people to lose their jobs, not just the people that screwed up.
I am not entirely sure the devs are aware of this problem and it’s widespread nature on high pop PVP servers.
I am pleased this thread finally got replies that weren’t purposely dismissive and made by people who are clearly impacted personally in any decision or action Blizz might make.
Donzia,
That statement sounds like this is a major issue when I don’t believe it is. Your posting is the first to report this as a problem. And you have tied it directly to multi-boxing.
The use of cross faction spying isn’t directly tied to multi-boxing:
You are clearly here to defend multiboxing at all costs and will ignore whatever facts or information you see necessary to defend your position.
I’d prefer to have this discussion with people that aren’t so severely biased, thanks.
Donzia,
What I said is:
Tell me which of those statements are wrong or that I misunderstood. If I didn’t understand correctly, then correct my misunderstanding.
Can I not say that this behavior is not necessary tied to multi-boxing?
Similarly, you like wise are tying this problem to multi-boxers.
I always laugh when rogues blame the Spy addon when they can’t sneak up on ‘unsuspecting’ players in a world of multiple account holders.
Nah they been doing this as long as you started posting on these forums. 
Not just multiboxers do it, streamers, some alliance/hordies that are R14 bound and serious… Trust me, it’s a thing, and has always been and will be.
As someone with more than 1 account, i don’t see how you can prove that a player is abusing multi boxing on a pvp server without reporting anything and everything that YOU may think is cheating in the hopes that a GM will care…but most likely there is no cheating going on. The vast majority of players have only a single account and the servers are over populated, you may be seeing a alliance player on discord with a horde buddy helping him out which is more likely than a dude parking a low lvl in spirit to help camp players.
With that said, having another account watch for a respawn of rich thorium, now that i can see. You don’t need to make a opposite faction to do that though and it’s not against the ToS either.
There likely is some limited exploitation going on sure, it needs to be proven though, and the GMs of today are not even a shadow of what they were back in vanilla where they actually were effective. A GM getting multiple reports from a player seems more likely to just ignore that player and view him or her as annoying, that is my experience when dealing with most GMs in classic. They are underpaid and will do the least required.
Ironic that this problem of spying on the other faction using another account is more apparent in a single realm world environment like Classic where everyone is now shoehorned into one ‘layer.’
Here is definitive proof of what I am talking about
IMGUR COM /a/ slabrLT
Not even trying to hide what they are doing with that character name.
So i guess logging my main out ontop of a chest and checking every 20 minutes is also such a horrible thing to do.
Sometimes i park it infront of ghost mushrooms and :gasp: get about 3-4 stacks a day.
who need extra accounts? you can add opposite faction real id friends and check where are they by WIM addon 
or just chat for info
Donzia,
Thank you for supplying information. I’ll say you have a point; but, I’m not sure if they are breaking any rules. (The later is not an argument. It is just a statement because I don’t know.)
The character has been reported for zone disruption so we will see what the GM’s say.
Parking characters to see spirits is not ok.