They've also completely borked up Usenet (Google Groups), including the choice to simply put big padlock on whatever zombie Usenet groups are being used for spam, making it impossible to, e.g., read the messages posted to alt.rock-n-roll around the time of Freddy Mercury's death. [1]

See also [2].

[1] https://groups.google.com/forum/?fromgroups=#!searchin/alt.r...

[2] https://news.ycombinator.com/item?id=10083938