1. They dropped anvils with a metadata of 1337 and a coloured name. Anvils normally use metadata to show how damaged they are, but above 3, placing one causes your game to crash (https://bugs.mojang.com/browse/MC-82677).

2. ~7:30 PM EST, June 22nd

3. 52;34

4. LostSpectre, lassebill

http://i.imgur.com/S2KdwyP.png

http://i.imgur.com/lIvw81D.png

Dealt with, thanks for reporting it.