EVE Online is a massive online multiplayer game, largest of its kind. In it players play as a spaceship pilot and master hundreds of different skills to fly a whole array of different type of ships in different situations. Players can join player owned and run corporations, which in turn are part of alliances of corporations, and fight each other for control of territory and resources.
In this battle in particular, two alliances clashed over the control of one system resulting in the largest, most expensive battle in any online game ever. When all was said and done, over 7500 individual players participated in the battle, with over 2500 in the same system at one time.
In EVE, there is one class of ship that is considered the most terrifying, and subsequently takes weeks for alliances to put together the resources and funds to build them. The Titan. In the 10 years EVE has been around, there have only been 12 titans destroyed in a single battle. In this fight, over 70 were lost.
In EVE, you can purchase game time cards for roughly $15 a pop for 30 days. You can also sell these time cards in game for in game currency to other players. If the alliance Pandemic Legion were to purchase enough of these cards to replace all the in game currency lost in the fight, it would come out to about $113,000 us dollars.