Ah well, they didn't buy the negotiating in bad faith and destroyed my pocos. Which is a shame. They have, however, put up their own. Which is great.
You see, if the opponent is determined enough, these things aren't really defensible by small groups. I have these guys on contacts on watch list. If they all log off I'll put their pocos into reinforced. When the pocos come out of reinforced what will probably happen is about 10 of them wait for 2 hours to defend while I do something else (play SWTOR probably). Then the pocos will be ok. Until they all log off again and I put them back into reinforced.
So you see the only defence is having enough players that you always have someone online. They could possibly get me if they have characters I don't know about but my assault force is enough that they'll probably need at least 3 to win a fight and once they do that I add them to watch list. In other words they have to burn character names to beat me, once burned I'll never attack when that character is online while I only have to update my pods and get new ships if killed then I'll go back in with the same characters.
Eventually they'll stop defending them. At which point if they're online I'll still wait but someone else, passing through the system might think "hay I can kill this thing" and then do so. If the pocos are coming out of reinforced and these guys are offline then I'll blow them up.
This is the core of asymmetrical warfare. What I have to do is occasionally log on and if I can see my targets are undefended blow them up. What they have to do is always be online all the time forever. Asymmetrical.
Because my target is an industrial corporation who call in favours from friends when they need military power there's a definite limit on how long they can sustain a defensive campaign. Every time I put the pocos into reinforced they have to call in a favour and get their mates to drop what they're doing and come help, help consisting of 2 hours doing nothing.
On the other hand it means I may need to adjust my Eve play. What I've been doing is semi-afk missioning in high sec. However once I antagonise these guys I need to leave them no target. Possibly missioning will be ok, I don't know if it will be possible to suicide gank a battleship if I fit it to run missions while being hard to gank. It's probably best simply to avoid giving any target at all. I might focus on station trading in Eve and other games out of Eve.
Alternatively I could just walk away. But I think you have to do something in a game like Eve other than just farm money. And if I achieve the diplomatic result I want I'll be able to do PI in their wormhole in peace forever. And I can't see how they can stop me harassing them unless they get very lucky and I lose both of the cloaked ships I have in the wormhole as scanners.