If you're familiar with an End User License Agreement (EULA) then you'll understand that the game publisher is legally bound to it. Just as any player is. The community managers can't directly come out and say, "yes, these parser are acceptable." For the simple reason that KDM and ACT are third party software.
However, they are allowed to hint at it:
Tamat's Input on ACT - AionSource - DPS meters -- bannable?
Posted 14 January 2010 - 03:23 PM
"I've replied to similar threads in the past, but I don't mind reiterating my stance on this. I love DPS parsers! Heck, I use them myself. We don't ban people for using DPS parsers but rather for the use of third party software that manipulates your characters movements. The software rule is in place to stop botters, hackers and cheaters of an equal feather -- not prevent our community from coming up with helpful programs like ACT.
For those who see this as a great excuse to use after being banned for botting: we can see the difference between damage parsers and bot software. If you're botting, we'll know."
Tamat later went on to quote from the EULA to clarify that all use of third party programs is not allowed.
Ayase's Input on KDM - AionSource - King's Damage Meter
Posted 11 February 2010 - 04:57 AM
"The application does imply modification of the game client (I'm primarily referring to the System.ovr file) and is in doing so in breach of the User Agreement (liability ensues). We want to keep the game fair and never hesitate to go after cheaters, users who automate their game play or otherwise exploit/hack. There's however a ladder of priority, and I'd be lying if I said that going after people deploying this seemingly 'harmless' tool is on the top of that list at this point. "
Conclusion
Can they ban you for using KDM or ACT? Yes.
Will they? No.
I have openly spoken about KDM and I have never tried to hide my in-game identity. (I'm Keiden and Kingofspades on Nezekan server.) I have also emailed the community managers requesting that they feature KDM in the "Eye on Community" series from the same email that my NCSoft master account is registered under. KDM does nothing to try to "hide" itself on your computer from the game client's anti-cheating protection.
At this moment there have been 1,722 downloads and 0 reports of bans connected to the use of KDM. If they decide to ban any one, I'm sure I will be the first. =p
Now, go download KDM and have fun.