Mata Hari was executed by a firing squad on Oct 15, 1917. It is still a little early for remembering her a century after her death. But it is not too early to remember that the news of her arrest were leaked to the press in June 1917 and her trial started on July 24th.
Today, we know enough of this story to be sure that the fame of Mata Hari as spy for the Germans was completely unjustified. She was framed, she was just a convenient scapegoat to blame for the troubles and the defeats of the French army in 1917, during the Great War.
It was a kangaroo court that condemned Mata Hari and, in more than one way, she was the victim of fake news. At that time, propaganda was still a relatively new technology that would see much more development in our times. We haven't seen anything yet!