Unsurprisingly, GoT fans were quick to spot Gemma's announcement and started posting updates online to alert everyone to the new casting.
"The internet went nuts. One of the lovely, lovely producers on Thrones called me into his office and said, 'This is very serious. We almost can’t employ you because of this.'"
Fortunately for Gemma, the GoT powers that be decided not to push the matter further and went ahead and hired her with just a warning.
This is a message for all of us, to be honest. Be very careful of what you post online - especially if you're ever cast in an epic TV series.