For a wildly successful author, having a dedicated fan-base can be something of a mixed blessing.
JK Rowling is very active on Twitter, where she has more than 9.5 million followers, and regularly engages with those who love her work.
The Harry Potter author also has frequent run-ins with critics and trolls - but those who fire barbs at her on social media tend to come of second best to this undisputed master of the Twitter take-down.
This week she's also had to deal with another undesirable side of Twitter celebrity - adoring messages from fans making plans for the day she dies: