Update: Take-Two says it targeted the Open IV project over "harassment issues," but was not targeting modding overall.

"Take-Two's actions were not specifically targeting single player mods. Unfortunately OpenIV enables recent malicious mods that allow harassment of players and interfere with the GTA Online experience for everybody. We are working to figure out how we can continue to support the creative community without negatively impacting our players," the company told Ars.

End update:

A Russian developer behind the popular Grand Theft Auto V modding tool Open IV said the project is being killed off in the wake of a cease-and-desist demand from game maker Take-Two. The tool has paved the way for all types of GTA modifications.

"Almost 10 years of my life were dedicated to @OpenIV and now the time is over," developer GooD-NTS tweeted.

On the OpenIV website, GooD-NTS explained that he got a cease-and-desist letter on June 5 accusing him of "Russian laws violations." The letter, he said, ordered Open IV to shutter because it allows "third parties to defeat security features of its software and modify that software in violations of Take-Two's rights."

He continues:

Going to court will take at least few months of our time and huge amount of efforts, and, at best, we'll get absolutely nothing. Spending time just to restore status quo is really unproductive, and all the money in the world can't compensate the loss of time. So, we decided to agree with their claims, and we're stopping distribution of OpenIV.

The Open IV tool is no longer available for download, and it won't be updated. PC Grand Theft Auto V gamers trying to launch Open IV are greeted with a message explaining that the service is "discontinued" because Take-Two said modding games is "an illegal activity and demands from us to discontinue the project."

Game mods have always existed in a legal gray area, and they have often operated via the tacit blessings of rights holders.

Take-Two did not respond for comment. In 2015, Ars brought word that Take-Two went to the house of the modders behind the FiveM project to shut the mod down because it contained "code designed to facilitate piracy."

The typical legal issues, regardless of country, usually involve end user agreements and intellectual property rights.

The Michigan Telecommunications and Technology Law Review has written that "as mods become more extensive, involved, and lucrative, they are increasingly running into legal issues, revolving mostly around violations of End User License Agreements (which, by and large, everyone accepts, but no one ever reads), and copyright infringement."

The article said that "copyright infringement is obvious where mods substantially copy other intellectual properties" or when they "alter or add to gameplay elements or stories."

GTA forums exploded in response with hundreds of complaints. One commenter hoped the announcement was a joke, while another suggested that Take-Two "has just removed a MASSIVE SELLING POINT."

Listing image by Ashley Richards