According to Blizzard, “Diablo, World of Warcraft, StarCraft and Hearthstone players may be impacted by high latency and disconnections during their gaming experience that are the result of a series of DDoS attacks on certain European online services.”
Thankfully despite the attacks, Blizzard has reassured gamers that Blizzard’s infrastructure remains intact and that not all their players have felt the effects of the attacks. “Although Blizzard’s infrastructure isn’t targeted, the disruption effects rippled and have been felt by a portion of our players’ population. While we are closely monitoring the situation we wanted to thank you for your patience and apologise for any inconvenience this may cause.”
We’re not sure if Blizzard has managed to sort the issue out by now, but in case you are playing any of those games and were wondering why it might be laggy, you now know the reason why and hopefully Blizzard will be able to sort this out soon.