Disaster is how what happened in the last few days in relation to anime leaking on the internet can be classified, Ranma 1/2, Re:Zero, Dandadan and others had episodes leaked which could end up causing a lot of problems later.
To begin with, 12 episodes of the Ranma 1/2 remake were leaked and the worst part is that the episodes have English subtitles, allowing people to watch them now, we still don’t know if they are all the episodes.
All episodes of the Terminator Zero animated series have also been leaked, as has the Gekijōban Mononoke: Karakasa film. Dandadan, as far as we can tell, has had 6 episodes leaked, with the rest likely to appear at any time.

Re:Zero is in a different situation, the first episode was leaked with French subtitles which indicates that this episode was leaked from another source.
Some claim that the leaked episode of Re:Zero 3 came from an event in France that was going to show the first episode early, and one of the people responsible for the event simply put the episode online.
The other leaks, from Dandadan, Ranma 1/2 came from an apparent hack on Netflix. The episodes are being made available on the torrent site Nyaa.