The “Karma Weapon Exploit” saw players selling Tier 2 weapons for 21 Karma - which is roughly 1/1000th of the weapons’ normal price. The buyers would then turn and sell the weapons at vendors for a massive gold profit.
In response, ArenaNet mass-banned 3000 players, while issuing 1000 72 hour suspensions to others.
In an open letter from lead producer Chris Whiteside:
Today we banned a number of players for exploiting Guild Wars 2. We take our community and the integrity of the game very seriously, and want to be clear that intentionally exploiting the game is unacceptable. The players we banned were certainly intentionally and repeatedly exploiting a bug in the game. We intended to send a very clear message that exploiting the game in this way will not be tolerated, and we believe this message now has been well understood.
We also believe and respect that people make mistakes. This is in fact the first example of a widespread exploit in the game. With this in mind, we are offering the members of our community who exploited the game a second chance to repair the damage that has been done.
Thus, just this once, we will offer to convert permanent bans to 72-hour suspensions. Should those involved want to accept this offer of reinstatement, contact us on our support website–support.guildwars.com—and submit a ticket through the “Ask a Question” tab. Please use the subject heading of “Karma Weapons Exploit Appeal”, then confirm in the body of your ticket that you will delete any items/currency that you gained from the exploit. You should submit only one ticket. Once you have done so, we will lower your ban to 72 hours, and following your re-activation we will check your account to make sure that you have honored your commitment. If that commitment is not hindered, we will re-terminate the account.
This is a first and final warning. Moving forward, please make sure you that when you see an exploitable part of the game, you report it and do not attempt to benefit from it.
Guild Wars 2 had a limited launch on the 25th August before its worldwide launch on the 28th. Players dealt with login and guild issues, but those that have played have raved about the game.