Google appears to have released a major update affecting movie-related websites in the US last week with big sites such as Slashfilm and TMZ losing lots of rankings. Slashfilm is down 86% according to Searchmetrics.
Apparently, Matt Cutts is investigating which makes it sound like the update was intentional but these legitimate blogs were hit unintentionally, very much like the original Panda update three years ago had some false positives.
Google has been under fire recently for showing links to pirated content at the top of the results for queries relating to House of Cards so this might be a reason for the recent update although it seems a bit too quick for that to have occurred.
Ironically one of the biggest winners last week (up 48%) was Movie4k.to which used to be Movie2k.to before it was shut down by the MPAA for copyright infringement.