Some 25,000 players who had bought a community-created weapon within Dota 2 discovered a new item in their inventories after Valve learned it had been copied directly from the MMO Aion.
Valve brought this up on its Steam Workshop blog, probably because 25,000 people noticed they no longer had "Timebreaker," a popular user-created mace that made it into the game earlier this summer. The item is a straight copy of "Marchutan's Blessed Mace" from Aion.
It sounds also like Valve wanted to make an example out of this, as "it took a lot of time for us to investigate and remedy the situation," wrote Dota designer Alden Kroll. While about 1,400 community-created items have been removed from Dota 2, this situation was different because it involved one that had actually gone on sale. "It becomes more complicated if a Workshop item becomes offered for sale on Steam or in a game, and the item later turns out to infringe on someone else's work," Kroll wrote.
The user who made the mace has been banned from the game and is going "to lose out on any proceeds from the sale of the item," said Kroll, who added that 24,603 users spent money on keys to open a chest and receive the mace. He repeated an appeal for the community to flag plagiarized contributions, and for contributors to create only original work and swear to that fact.
Respecting Intellectual Property [Steam Workshop Blog]