If you follow competitive Dota very closely then you probably already know that some serious shit has been going down ever since the start of the G-1 League western qualifiers.
We've now had three series in row where one of the teams have suffered what many are claiming are DDoS attacks. While I'm still somewhat skeptical of individual players being DDoS'd, the fact remains that during the past three best-of-three matches in the G-1 one or more players have had their internet connection completely shut off only to mysteriously return after the completion of the series or the postponement of the match.
I was up at the wee hours of the morning to watch the series between Kaipi/Empire and Qpad/Dignitas so I got bare witness to this myself. I spent both matches reading twitters and checking steam page and both PieLieDie from Kaipi and Sneyking and Fogged from Dignitas were all completely cut off from rejoining the games or communicating with their teams or the tournament organizers until after the completion of both series. It was very a very strange thing to watch with players discussing possible courses of action in the game chat as well as claiming they were aware of the previous attacks and had taken precautions only for them to fail.
There's a lot of speculation as to what the fuck is happening and why. The prevailing theory seems to be that the malicious party is scraping player IPs off of Skype, or perhaps even Steam Friends, but the motives as to why are still unknown. Several people have pointed towards Dota 2 Item and real money betting sites as possible motivation for trying to rig games through attack, though I put little stock in this theory as Kaipi was clearly the underdog in their match up but were still targeted. It could be that these people are just out to ruin Dota 2, though I'd certainly like to believe there isn't anyone out there spending the time and resources necessary to ruin something as benign as a fucking competitive gaming tournament for no apparent reason.
Whatever you believe, the fact remains that if actions isn't taken soon the whole western qualifier is going to go down the shitter real fast. While Kaipi was able to clean up their series down a man, the game between Qpad and Dignitas was postponed until further notice. With more G-1 games scheduled throughout the week, including a match-up with winner of the aforementioned series, it's unknown how these attacks will affect the qualifiers or what actions will be taken to prevent further attacks.
Truly it is a sad day when even video games are not safe from bitter people with stellar upload rates.