Many subreddits all across reddit are closing up shop in protest to reddit's new API policies. Some subreddits will go dark for 48 hours, so are going out indefinitely. This includes some of the biggest subreddits like r/videos, r/funny, r/music, r/todayilearned, r/gaming, etc.
r/hockey is set to go dark for 48 hours, and r/leafs is shutting down indefinitely
Boston Bruins, sabres, DetroitRedWings, Habs, OttawaSenators, devils, NewYorkIslanders, rangers, Flyers, penguins, caps, Hawks, ColoradoAvalanche, Predators, stlouisblues, winnipegjets, CalgaryFlames, SanJoseSharks, SeattleKraken, and canucks have all announced that they will be participating too to some extent.