We first saw the news on ArsTechnica.
Twitch is a video platform and online gamer community that lets people watch each other play video games via a livestream. It's a very popular service, and accounts for a massive amount of Web traffic in the U.S.
Since last week, millions of people have been collaborating to finish one game of Pokémon Red, the original Pokémon game for Game Boy.
As of Wednesday, Twitch had seen millions of unique viewers and over 100,000 peak concurrent viewers.
"The unique nature and huge chat participation in the TwitchPlaysPokemon experiment has put enormous (and unforeseen) stress on our chat system," Twitch Director of Customer Experience Jason Maestas wrote on the company blog.
Twitch moved the game to its own dedicated server on Sunday, something it typically does for large online gaming events like League of Legends tournaments. That helped, but there were still some "fundamental issues" with its chat infrastructure. As the experiment goes on, Twitch plans to continue to tweak its system so that it can handle the massive load.
You can watch the action here.