To me, this essentially equates to 'guns don't kill people, people kill people'. Maybe a little extreme and in many people's eyes not even an accurate statement – however, that is irrelevant. It is saying that although the medium may be the message, it's not just the medium that causes the issue, it's how it is utilized. Now, I'm not disregarding the medium and saying it's actually the message that's more important. Rather that a medium is not an issue unless it is being posted on the platform, without the posts (or the messages), the medium itself would be non-existent. This just reminds us the importance of the message too being place on the medium of our choice.