It is happening on Chronus not sure if it happening as often on other servers.
Since most toons have AOE skills or skills that target an AOE people will flag on you then train a bunch of mobs, when tank AOE hates they flag even without holding control down.
Also a healer or enchanter chain heals will heal the flagged person even out of party since it heals the closest 10 people to you.
I know this is not how the game mechanics were intended and higher clans are using it to grief lower clans instead of having to pk them and go red.
I love how Korea changes game rules and it does not work the same in NA because we play by different standards.
Just like grouping doesn't work the same in NA/Euro as it does in Korea.
In NA/Euro the server spans 13 time zones, in Korea its spans 1, in Japan 1, in China 3.
NA/Euro even in NA spans 5 time zones (6 if you include SA). That is why soloing and small parties were more popular in NA/Euro cause of the difficulty of finding groups at the time you are logged on. There is no prime time for all of the NA server as seen by the login in chart there is constant high activity throughout the day.
However post 85 you cannot xp solo or duo or even trio. They are alienating a large section of the game by the exploitation of pvp rules and having to hunt in a party.