I've been witnessing this for quite a long time now. I've seen many players abuse the system of cross-realm (being for example grouped with someone from a different realm).
1) With the add-on Oqueue : People who want to farm rares such as Krol, warbringers, Lon and so on.
2) With the help of friends : well in that case, it seems more legit because you dont abuse other players in raid teams who expect you to come to face celestials, ToT or whichever bosses you"re intending to kill.
3) The abuse in Pvp : example : i go to a low-populated Pvp server, i kill some people cause it's funny then people come to help "victims", i just click on "leave the party" and it's alright.
4) Stealing of "natural" ressources of the realm : What a dream for gatherers to go to a low-pop realm : Goldthorns.... and rare ressources already that are now being farmed by people from realms not entitled to get these.
They are mostly from highly populated realms (in the EU : Sylvanas, Silvermoon, Hyjal....) so they do have the advantages of being part of these huge realms (AH full, raids, activities on the channels.......) and also, thanks to this Cross-realm thing all the advantages of the dead realms where, up till now, people were suffering but could enjoy a little quiet, could enjoy having ressources, the only little pleasures they had.
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So i wondered what you guys think about this ? Should it be allowed to abuse cross-realm system ?