What was probably the biggest repository of hentai and non-hentai doujins is now dead. Two decades worth of images and galleries have vanished from this earth, including now impossible to find stuff from the 80's and 90's. People have compared this loss to the burning of the Library of Alexandria.
Reasons as to why it went down include rumors of new legislation against loli/shotacon in the Netherlands (where the server was hosted), Article 13 being passed in the EU causing all the copyrighted material to be illegal, and the head admin, Tenboro just not wanting to host it anymore. People were given twelve hours to save what they can, and then the site vanished with its hundreds of terabytes of content. This was the site Ex-hentai, the hidden and unfiltered version of E-hentai which will also go down in about six months. Many other hentai sites were just mirrors of what was posted between these two websites, nHentai being one example. It only used a bot to download and re-upload content from the two sites, and has never allowed directly uploading to the site.
Let this be a lesson to back up and download what you like, because digital information is easy to lose. Two decades of archival rested on the shoulders of one man, and he could no longer bear the weight.