Pewdiepie said that when he hits 50,000,000 subscribers he would delete his channel, and he kept his promise. Check out his video of the Pewd's deleting his channel.
Whether the reason Pewdiepie deleted his channel is for the lols, or because Youtube wanting to be an ass... It's actually in the video why he did this. What will the internet become now that PewDie Pie has deleted his channel that I'm not even subscribed too.