Legality
It appears that Valve Software regards WON2 with suspicion and hostility. In March 2006 a takedown notice cost the project its host, forcing the project offline between approximately the 18th and the 24th of that month. Later the host claimed that within two weeks it would stop offering webhosting services altogether, indicating that the takedown notice was not the primary reason services were lost.
The WON2 network's legal status has been questioned by some, from country to country. The project maintains that it is within the bounds of Valve's EULA for Half-Life, although it notes that all recent Valve games now forbid modifications like theirs. WON2 also mentions that in some countries the server patch used to circumvent the authentication servers would be illegal to use. The project has offered its own legal analysis on the subject, although so far no legal action has been pursued beyond takedown notices. People within the WON2 project believe Valve can do very little to shut them down, due to its decentralized nature and that it is run primarily from outside of the United States.
Read more about this topic: WON2