[diggan]

Went to Wikipedia to confirm, https://en.wikipedia.org/wiki/User_revolt#Digg :

> In 2007 in the AACS encryption key controversy

> When Digg redesigned their website in 2010 the community revolted and used the platform to advertise a user migration to competitor Reddit

So while both seems to be classified as "user revolt", the redesign seems to be acknowledged as causing the migration to reddit. Of course, not 100% sure how accurate that is, but seems to match my own memory at least.