Not sure how I missed this thread exactly, but let me clarify a bit about what ebilone was saying; the guild in question that we did face that one time was using romeo's, atleast two of their members were anyways, there was a rogue who was constantly flying into our castle to hide out (and into our throne room) who I killed a number of times. The mage when hit from standing still would immediately be unattackable even with range, and could always see both Ebi and I in hide, it was far from isolated, the other members seemed to be behaving themselves but the one mage kept using Romeo's to avoid being attackable, I did manage to kill them a few times, but it was a struggle. I'm not too sure if their guild realized it or not to be honest, but that one rogue sure did.
I honestly think that people should download Romeo to know what it's capable of to be honest, using it is one of the most non sportsmanship-like thing you can do in siege, that's not to say that using it out of siege is good, it's not.
However you can recognize exactly what they're doing if you're seen how the interface works, especially since it comes with a see rogues in hide option.
There used to be an old way to mess with Ragnarok Online files so you could make yourself wear a GM costume and could see people in hide/cloak, it works the same way, everything is client sided in this game unfortunately due to poor programming.
But people should just use the honor code, the accessibility to 'hacks' in this game is very high, unfortunately any nub or 'script kiddie' can get ahold of them without any major struggle. I quit Mabinogi because of a similar issue, though luckily on here people aren't able to dupe and when we pick up stackable items we don't gain all the stats from our titles each time we pick something up..
Also jfyi never saw a rouge who was walking around in hide only low level ones, so never ran into that particular glitch myself.
EDIT: Oh also it's easy to bleed spec, so those complaining about how walls get killed so fast need to learn how to