The actress, who stars this week in one-off drama 'Cyberbully' an intimate piece showing a young teenager's best and worst experiences with the internet, tells HuffPostUK the abuse she suffered kicked off when she was still at school, but had won her role as Arya Stark in HBO's epic hit:
"I don't come from a place where opportunities like this come around. Nobody at my school had ever done an audition for anything, and all of a sudden I was in a series and on television, and I was a natural target.
"Everyone at school wanted to do something, but I don't come from a place where people make a name for themselves, and I was going to be one of those people, too. I was just going to be born there, have my kids there, that was just how I saw life.
"And all of a sudden I got this amazing opportunity to go off and do something else, and to everyone else it was just an enormous kick, and I get it, I totally get it."
Maisie, whose role in 'Game of Thrones' has seen her character Arya transform from a young girl forced to watch her father die, into a fearsome warrior in her own right. It's clear Maisie is just as clear-headed and forthright herself, particularly when asked to describe her own worst experience on the internet...
"In a word, 'Formspring' or 'Askfm' (both Q&A forum sites for fans).
"If anyone reading this has an account, my first advice is to delete it straight away, because I don't have time for that anymore.
"There are good cases, but there are far too many bad cases. Whenever I read a story and askfm is involved, I just… * Maisie visibly shivers, then brightens for talk on her favourite example of what the internet can do...
"One of my favourite YouTubers is Troye Sivan. I tweeted about something, he tweeted back, thanking me for the support. About a year ago, he came out as gay, and I did a little video expressing my support. I didn't know the guy, but I thought it was important. Little things like that mean a lot."
'Cyberbully' will be shown on Channel this Thursday 15 January at 9pm. Watch the trailer below...