The first example comes from The Secret World. Funcom held a Mayan zombie apocalypse event to celebrate the move to a buy-to-play model and the coming end of the world. As part of the event the top 1000 scoring players would receive a title and the top 100 would receive an in-game pet. On 7 January that planned changed due to some players discovering a way to "exploit the mechanics and reach impossible amounts of points which in turn alters the rankings to unrealistic results." In this example of players exploiting game mechanics all that was at stake were some titles and pets. Funcom resolved the situation by giving all players the title and pet.
A more serious situation arose during Guild Wars 2's Wintersday holiday event. On 3 January Massively described the exploit.
"Players were able to use a single high-level snowflake, a Black Lion salvage kit, and a bit of metal to generate effectively limitless globs of ectoplasm (which are kind of a cornerstone of the economy, as they're used in the majority of high-end items). The exploit was closed, but not before an apparently large number of people took advantage of it."Many players are upset with the permanent bans issued by ArenaNet but this is not the first big exploit encountered in the game. Back in August over 3,000 players were permanently banned for using an exploit for crafting high-level weapons “one thousandth of their normal price.” ArenaNet relented and reduced many of the bans down to 72 hours but apparently the event did not deter many from taking similar actions over the holidays.
In the wake of major botting problems in addition to the previous exploit ArenaNet is taking a hard line with violators. ArenaNet Support Liason Gaile Gray issued the following statement on the GW2 forums: