Excerpt from this article:
Social media platforms, through the digital traces they create, will lend these passing events greater permanence. The social media archive of images, videos and hashtags is, of course, ephemeral in its own way (posts have limited circulation, a narrow window in which they are viewed and are vulnerable to deletion and loss). But it is important to understand that social media plays more than a documentary role. They enable unique and spontaneous commemorative practices such as people sharing photographs of themselves with tattoos, balloons and other memorials that need to be studied further. They create a shared sense of commemoration between those present at public memorials and those participating online.