A holiday event turned exploit opportunity ended with permanent bans for some players of Guild Wars 2. The Wintersday event inadvertently opened an exploit that allowed players to print their own money, figuratively speaking. ArenaNet promptly put them on the naughty list.
Massively reports that players could use one particular snowflake, a Black Lion salvage kit, and combine it with some metal to make near-limitless supplies of ectoplasm. Ecto is used to craft most of the high-end items, so flooding the market with it would have its share of side-effects. The exploit was subsequently closed, and bans issued.
"I've seen the numbers, and the damage to the economy could have been substantial, if the exploit wasn’t closed down and if these people were allowed to use their ill-gotten gains," ArenaNet support liaison Gaile Gray said on the game's forum. "People whose accounts were terminated were the worst offenders. I'm talking a lot of ill-gotten gains that posed a significant potential impact on the economy."
Grey then addressed the original poster directly, who complained of being banned. "I know the OP will disagree. But we've been more than kind, in the past, and everyone needs to own up to his/her errors and recognize: We all are part of the game economy, and those who exploit it are hurting the rest of us."