Hacking is a constant issue. A friend of mine was hosting a private hive, and I decided to try and use it to begin a DayZ LP. Another friend of ours and I spent an hour or two getting our freshly spawned characters to the same location ready for recording, got things all set up, but only 10 minutes into the first recording a few people had joined and were spawning vehicles and teleporting all over the place.
We didn't realise they were hacking at first, we were just surprised they had a chopper so soon but the server'd been up a while so it was possible. However, they managed to spot us in a house without windows, landed, someone ran up to the house and called for us to come out or they'd shoot. We obliged, it was kinda cool in the recording as I'd just finished talking about players being almost worse than zombies. When they found out we were fresh characters, they offered to help us, bonus, then out of nowhere a car drove up. We were a bit stunned, but obligingly got inside when asked, the car (and us) then teleported over to the chopper, where the hackers had kindly spawned a loot pile of every gun in the game (and some which aren't in it, normally).
Although they were kindly, the fact they were just twinking the game pretty much ruined the feel instantly. We politely refused their help and logged off. It was a day or so before we tried recording again, this time on a public server, which so far is going well (if you're interested, the first episode is
here ). The friend who hosted the server is a bit worried though, mostly because the hackers were able to effectively inject data into the server's database with such ease, he's not sure how he could stop it, as battle-eye was enabled throughout.
All in all, hacking kinda destroys this game, when it happens. More so than other games I feel, because one of the main draws of Day-Z is the harsh environment and difficulty. Take that away, and there's not really much left :/
For what it's worth though, if you're able to prevent, or at least limit hacking, I'd very much like to play on a B12 server